<p class="" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Ubuntu, "Helvetica Neue", Helvetica, Arial, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei UI", "Microsoft YaHei", "Source Han Sans CN", sans-serif, "Apple Color Emoji", "Segoe UI Emoji"; margin-top: 0px; margin-bottom: 0px; font-size: 15px; line-height: 1.75; color: rgb(5, 7, 59); text-wrap: wrap;">在Node.js中，可以使用Express框架与MySQL数据库进行交互。下面是一个简单的示例代码，演示如何使用Express框架操作MySQL数据库：</p><ol style="box-sizing: border-box; padding: 0px 0px 0px 32px; -webkit-font-smoothing: antialiased; list-style-position: outside; list-style-image: none; font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Ubuntu, "Helvetica Neue", Helvetica, Arial, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei UI", "Microsoft YaHei", "Source Han Sans CN", sans-serif, "Apple Color Emoji", "Segoe UI Emoji"; margin-top: 14px; margin-bottom: 1em; font-size: 15px; line-height: 1.75; color: rgb(5, 7, 59); text-wrap: wrap;" class=" list-paddingleft-2"><li><p>安装MySQL模块和Express模块</p></li></ol><p class="" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Ubuntu, "Helvetica Neue", Helvetica, Arial, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei UI", "Microsoft YaHei", "Source Han Sans CN", sans-serif, "Apple Color Emoji", "Segoe UI Emoji"; margin-top: 14px; margin-bottom: 0px; font-size: 15px; line-height: 1.75; color: rgb(5, 7, 59); text-wrap: wrap;">首先，需要在Node.js项目中安装MySQL模块和Express模块，可以通过npm进行安装：</p><pre style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; font-family: SFMono-Regular, Consolas, "Liberation Mono", Menlo, Courier, monospace; margin-top: 14px; margin-bottom: 0px; font-size: 15px; overflow: auto; border-radius: 6px; color: rgb(5, 7, 59);"><code class="language-shell" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; font-family: SFMono-Regular, Consolas, "Liberation Mono", Menlo, Courier, monospace; margin: 0px; font-size: 1em; tab-size: 4;"><table class="hljs hljs-ln"><tbody style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;" class="firstRow"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;">npm install mysql express</td></tr></tbody></table></code></pre><ol style="box-sizing: border-box; padding: 0px 0px 0px 32px; -webkit-font-smoothing: antialiased; list-style-position: outside; list-style-image: none; font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Ubuntu, "Helvetica Neue", Helvetica, Arial, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei UI", "Microsoft YaHei", "Source Han Sans CN", sans-serif, "Apple Color Emoji", "Segoe UI Emoji"; margin-top: 14px; margin-bottom: 1em; font-size: 15px; line-height: 1.75; color: rgb(5, 7, 59); text-wrap: wrap;" class=" list-paddingleft-2"><li><p>引入MySQL模块和Express模块</p></li></ol><p class="" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Ubuntu, "Helvetica Neue", Helvetica, Arial, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei UI", "Microsoft YaHei", "Source Han Sans CN", sans-serif, "Apple Color Emoji", "Segoe UI Emoji"; margin-top: 14px; margin-bottom: 0px; font-size: 15px; line-height: 1.75; color: rgb(5, 7, 59); text-wrap: wrap;">在Node.js中操作MySQL数据库需要使用require('mysql')模块，而Express框架则可以使用require('express')模块。例如：</p><pre style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; font-family: SFMono-Regular, Consolas, "Liberation Mono", Menlo, Courier, monospace; margin-top: 14px; margin-bottom: 0px; font-size: 15px; overflow: auto; border-radius: 6px; color: rgb(5, 7, 59);"><code class="language-javascript" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; font-family: SFMono-Regular, Consolas, "Liberation Mono", Menlo, Courier, monospace; margin: 0px; font-size: 1em; tab-size: 4;"><table class="hljs hljs-ln"><tbody style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;" class="firstRow"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><span class="hljs-keyword" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(121, 40, 161); line-height: 24px;">const</span> mysql = <span class="hljs-built_in" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(170, 93, 0); line-height: 24px;">require</span>(<span class="hljs-string" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: green; line-height: 24px;">'mysql'</span>);</td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><span class="hljs-keyword" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(121, 40, 161); line-height: 24px;">const</span> express = <span class="hljs-built_in" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(170, 93, 0); line-height: 24px;">require</span>(<span class="hljs-string" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: green; line-height: 24px;">'express'</span>);</td></tr></tbody></table></code></pre><ol style="box-sizing: border-box; padding: 0px 0px 0px 32px; -webkit-font-smoothing: antialiased; list-style-position: outside; list-style-image: none; font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Ubuntu, "Helvetica Neue", Helvetica, Arial, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei UI", "Microsoft YaHei", "Source Han Sans CN", sans-serif, "Apple Color Emoji", "Segoe UI Emoji"; margin-top: 14px; margin-bottom: 1em; font-size: 15px; line-height: 1.75; color: rgb(5, 7, 59); text-wrap: wrap;" class=" list-paddingleft-2"><li><p>创建Express应用程序并连接MySQL数据库</p></li></ol><p class="" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Ubuntu, "Helvetica Neue", Helvetica, Arial, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei UI", "Microsoft YaHei", "Source Han Sans CN", sans-serif, "Apple Color Emoji", "Segoe UI Emoji"; margin-top: 14px; margin-bottom: 0px; font-size: 15px; line-height: 1.75; color: rgb(5, 7, 59); text-wrap: wrap;">在Express应用程序中，可以通过调用mysql.createConnection()方法来创建与MySQL数据库的连接。例如：</p><pre style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; font-family: SFMono-Regular, Consolas, "Liberation Mono", Menlo, Courier, monospace; margin-top: 14px; margin-bottom: 0px; font-size: 15px; overflow: auto; border-radius: 6px; color: rgb(5, 7, 59);"><code class="language-javascript" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; font-family: SFMono-Regular, Consolas, "Liberation Mono", Menlo, Courier, monospace; margin: 0px; font-size: 1em; tab-size: 4;"><table class="hljs hljs-ln"><tbody style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;" class="firstRow"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><span class="hljs-keyword" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(121, 40, 161); line-height: 24px;">const</span> app = <span class="hljs-title function_" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(0, 127, 170); line-height: 24px;">express</span>();</td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><span class="hljs-keyword" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(121, 40, 161); line-height: 24px;">const</span> connection = mysql.<span class="hljs-title function_" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(0, 127, 170); line-height: 24px;">createConnection</span>({</td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><span class="hljs-attr" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;">host</span>: <span class="hljs-string" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: green; line-height: 24px;">'localhost'</span>,</td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><span class="hljs-attr" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;">user</span>: <span class="hljs-string" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: green; line-height: 24px;">'root'</span>,</td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><span class="hljs-attr" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;">password</span>: <span class="hljs-string" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: green; line-height: 24px;">'password'</span>,</td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><span class="hljs-attr" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;">database</span>: <span class="hljs-string" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: green; line-height: 24px;">'mydatabase'</span> </td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;">});</td></tr></tbody></table></code></pre><ol style="box-sizing: border-box; padding: 0px 0px 0px 32px; -webkit-font-smoothing: antialiased; list-style-position: outside; list-style-image: none; font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Ubuntu, "Helvetica Neue", Helvetica, Arial, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei UI", "Microsoft YaHei", "Source Han Sans CN", sans-serif, "Apple Color Emoji", "Segoe UI Emoji"; margin-top: 14px; margin-bottom: 1em; font-size: 15px; line-height: 1.75; color: rgb(5, 7, 59); text-wrap: wrap;" class=" list-paddingleft-2"><li><p>查询数据</p></li></ol><p class="" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Ubuntu, "Helvetica Neue", Helvetica, Arial, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei UI", "Microsoft YaHei", "Source Han Sans CN", sans-serif, "Apple Color Emoji", "Segoe UI Emoji"; margin-top: 14px; margin-bottom: 0px; font-size: 15px; line-height: 1.75; color: rgb(5, 7, 59); text-wrap: wrap;">在Express应用程序中，可以使用mysql.query()方法来执行SQL查询语句。例如：</p><pre style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; font-family: SFMono-Regular, Consolas, "Liberation Mono", Menlo, Courier, monospace; margin-top: 14px; margin-bottom: 0px; font-size: 15px; overflow: auto; border-radius: 6px; color: rgb(5, 7, 59);"><code class="language-javascript" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; font-family: SFMono-Regular, Consolas, "Liberation Mono", Menlo, Courier, monospace; margin: 0px; font-size: 1em; tab-size: 4;"><table class="hljs hljs-ln"><tbody style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;" class="firstRow"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;">app.<span class="hljs-title function_" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(0, 127, 170); line-height: 24px;">get</span>(<span class="hljs-string" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: green; line-height: 24px;">'/users'</span>, <span class="hljs-keyword" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(121, 40, 161); line-height: 24px;">function</span> (<span class="hljs-params" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(170, 93, 0); line-height: 24px;">req, res</span>) {</td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><span class="hljs-keyword" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(121, 40, 161); line-height: 24px;">const</span> sql = <span class="hljs-string" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: green; line-height: 24px;">'SELECT * FROM users'</span>;</td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;">connection.<span class="hljs-title function_" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(0, 127, 170); line-height: 24px;">query</span>(sql, <span class="hljs-keyword" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(121, 40, 161); line-height: 24px;">function</span> (<span class="hljs-params" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(170, 93, 0); line-height: 24px;">error, results, fields</span>) {</td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><span class="hljs-keyword" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(121, 40, 161); line-height: 24px;">if</span> (error) <span class="hljs-keyword" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(121, 40, 161); line-height: 24px;">throw</span> error;</td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;">res.<span class="hljs-title function_" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(0, 127, 170); line-height: 24px;">json</span>(results);</td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;">});</td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;">});</td></tr></tbody></table></code></pre><ol style="box-sizing: border-box; padding: 0px 0px 0px 32px; -webkit-font-smoothing: antialiased; list-style-position: outside; list-style-image: none; font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Ubuntu, "Helvetica Neue", Helvetica, Arial, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei UI", "Microsoft YaHei", "Source Han Sans CN", sans-serif, "Apple Color Emoji", "Segoe UI Emoji"; margin-top: 14px; margin-bottom: 1em; font-size: 15px; line-height: 1.75; color: rgb(5, 7, 59); text-wrap: wrap;" class=" list-paddingleft-2"><li><p>插入数据</p></li></ol><p class="" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Ubuntu, "Helvetica Neue", Helvetica, Arial, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei UI", "Microsoft YaHei", "Source Han Sans CN", sans-serif, "Apple Color Emoji", "Segoe UI Emoji"; margin-top: 14px; margin-bottom: 0px; font-size: 15px; line-height: 1.75; color: rgb(5, 7, 59); text-wrap: wrap;">在Express应用程序中，可以使用mysql.query()方法来执行SQL插入语句。例如：</p><pre style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; font-family: SFMono-Regular, Consolas, "Liberation Mono", Menlo, Courier, monospace; margin-top: 14px; margin-bottom: 0px; font-size: 15px; overflow: auto; border-radius: 6px; color: rgb(5, 7, 59);"><code class="language-javascript" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; font-family: SFMono-Regular, Consolas, "Liberation Mono", Menlo, Courier, monospace; margin: 0px; font-size: 1em; tab-size: 4;"><table class="hljs hljs-ln"><tbody style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;" class="firstRow"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;">app.<span class="hljs-title function_" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(0, 127, 170); line-height: 24px;">post</span>(<span class="hljs-string" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: green; line-height: 24px;">'/users'</span>, <span class="hljs-keyword" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(121, 40, 161); line-height: 24px;">function</span> (<span class="hljs-params" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(170, 93, 0); line-height: 24px;">req, res</span>) {</td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><span class="hljs-keyword" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(121, 40, 161); line-height: 24px;">const</span> sql = <span class="hljs-string" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: green; line-height: 24px;">'INSERT INTO users (name, email) VALUES (?, ?)'</span>;</td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><span class="hljs-keyword" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(121, 40, 161); line-height: 24px;">const</span> values = [req.<span class="hljs-property" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;">body</span>.<span class="hljs-property" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;">name</span>, req.<span class="hljs-property" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;">body</span>.<span class="hljs-property" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;">email</span>];</td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;">connection.<span class="hljs-title function_" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(0, 127, 170); line-height: 24px;">query</span>(sql, values, <span class="hljs-keyword" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(121, 40, 161); line-height: 24px;">function</span> (<span class="hljs-params" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(170, 93, 0); line-height: 24px;">error, results, fields</span>) {</td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><span class="hljs-keyword" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(121, 40, 161); line-height: 24px;">if</span> (error) <span class="hljs-keyword" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(121, 40, 161); line-height: 24px;">throw</span> error;</td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;">res.<span class="hljs-title function_" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(0, 127, 170); line-height: 24px;">json</span>(results);</td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;">});</td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;">});</td></tr></tbody></table></code></pre><ol style="box-sizing: border-box; padding: 0px 0px 0px 32px; -webkit-font-smoothing: antialiased; list-style-position: outside; list-style-image: none; font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Ubuntu, "Helvetica Neue", Helvetica, Arial, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei UI", "Microsoft YaHei", "Source Han Sans CN", sans-serif, "Apple Color Emoji", "Segoe UI Emoji"; margin-top: 14px; margin-bottom: 1em; font-size: 15px; line-height: 1.75; color: rgb(5, 7, 59); text-wrap: wrap;" class=" list-paddingleft-2"><li><p>更新数据</p></li></ol><p class="" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Ubuntu, "Helvetica Neue", Helvetica, Arial, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei UI", "Microsoft YaHei", "Source Han Sans CN", sans-serif, "Apple Color Emoji", "Segoe UI Emoji"; margin-top: 14px; margin-bottom: 0px; font-size: 15px; line-height: 1.75; color: rgb(5, 7, 59); text-wrap: wrap;">在Express应用程序中，可以使用mysql.query()方法来执行SQL更新语句。例如：</p><pre style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; font-family: SFMono-Regular, Consolas, "Liberation Mono", Menlo, Courier, monospace; margin-top: 14px; margin-bottom: 0px; font-size: 15px; overflow: auto; border-radius: 6px; color: rgb(5, 7, 59);"><code class="language-javascript" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; font-family: SFMono-Regular, Consolas, "Liberation Mono", Menlo, Courier, monospace; margin: 0px; font-size: 1em; tab-size: 4;"><table class="hljs hljs-ln"><tbody style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;" class="firstRow"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;">app.<span class="hljs-title function_" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(0, 127, 170); line-height: 24px;">put</span>(<span class="hljs-string" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: green; line-height: 24px;">'/users/:id'</span>, <span class="hljs-keyword" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(121, 40, 161); line-height: 24px;">function</span> (<span class="hljs-params" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(170, 93, 0); line-height: 24px;">req, res</span>) {</td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><span class="hljs-keyword" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(121, 40, 161); line-height: 24px;">const</span> sql = <span class="hljs-string" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: green; line-height: 24px;">'UPDATE users SET name = ? WHERE id = ?'</span>;</td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><span class="hljs-keyword" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(121, 40, 161); line-height: 24px;">const</span> values = [req.<span class="hljs-property" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;">body</span>.<span class="hljs-property" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;">name</span>, req.<span class="hljs-property" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;">params</span>.<span class="hljs-property" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;">id</span>];</td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;">connection.<span class="hljs-title function_" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(0, 127, 170); line-height: 24px;">query</span>(sql, values, <span class="hljs-keyword" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(121, 40, 161); line-height: 24px;">function</span> (<span class="hljs-params" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(170, 93, 0); line-height: 24px;">error, results, fields</span>) {</td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><span class="hljs-keyword" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(121, 40, 161); line-height: 24px;">if</span> (error) <span class="hljs-keyword" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(121, 40, 161); line-height: 24px;">throw</span> error;</td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;">res.<span class="hljs-title function_" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(0, 127, 170); line-height: 24px;">json</span>(results);</td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;">});</td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;">});</td></tr></tbody></table></code></pre><p><br/></p>
文章列表
<p class="" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Ubuntu, "Helvetica Neue", Helvetica, Arial, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei UI", "Microsoft YaHei", "Source Han Sans CN", sans-serif, "Apple Color Emoji", "Segoe UI Emoji"; margin-top: 0px; margin-bottom: 0px; font-size: 15px; line-height: 1.75; color: rgb(5, 7, 59); text-wrap: wrap;">在Node.js中，可以使用Express框架来定义JSONP接口。JSONP是一种通过动态添加script标签来请求跨域数据的技术，它可以在服务器端返回JavaScript代码，然后在客户端执行该代码以获取数据。</p><p class="" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Ubuntu, "Helvetica Neue", Helvetica, Arial, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei UI", "Microsoft YaHei", "Source Han Sans CN", sans-serif, "Apple Color Emoji", "Segoe UI Emoji"; margin-top: 14px; margin-bottom: 0px; font-size: 15px; line-height: 1.75; color: rgb(5, 7, 59); text-wrap: wrap;">下面是一个使用Express框架定义JSONP接口的示例代码：</p><ol style="box-sizing: border-box; padding: 0px 0px 0px 32px; -webkit-font-smoothing: antialiased; list-style-position: outside; list-style-image: none; font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Ubuntu, "Helvetica Neue", Helvetica, Arial, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei UI", "Microsoft YaHei", "Source Han Sans CN", sans-serif, "Apple Color Emoji", "Segoe UI Emoji"; margin-top: 14px; margin-bottom: 1em; font-size: 15px; line-height: 1.75; color: rgb(5, 7, 59); text-wrap: wrap;" class=" list-paddingleft-2"><li><p>安装Express模块</p></li></ol><p class="" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Ubuntu, "Helvetica Neue", Helvetica, Arial, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei UI", "Microsoft YaHei", "Source Han Sans CN", sans-serif, "Apple Color Emoji", "Segoe UI Emoji"; margin-top: 14px; margin-bottom: 0px; font-size: 15px; line-height: 1.75; color: rgb(5, 7, 59); text-wrap: wrap;">首先，需要在Node.js项目中安装Express模块，可以通过npm进行安装：</p><pre style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; font-family: SFMono-Regular, Consolas, "Liberation Mono", Menlo, Courier, monospace; margin-top: 14px; margin-bottom: 0px; font-size: 15px; overflow: auto; border-radius: 6px; color: rgb(5, 7, 59);"><code class="language-shell" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; font-family: SFMono-Regular, Consolas, "Liberation Mono", Menlo, Courier, monospace; margin: 0px; font-size: 1em; tab-size: 4;"><table class="hljs hljs-ln"><tbody style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;" class="firstRow"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;">npm install express</td></tr></tbody></table></code></pre><ol style="box-sizing: border-box; padding: 0px 0px 0px 32px; -webkit-font-smoothing: antialiased; list-style-position: outside; list-style-image: none; font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Ubuntu, "Helvetica Neue", Helvetica, Arial, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei UI", "Microsoft YaHei", "Source Han Sans CN", sans-serif, "Apple Color Emoji", "Segoe UI Emoji"; margin-top: 14px; margin-bottom: 1em; font-size: 15px; line-height: 1.75; color: rgb(5, 7, 59); text-wrap: wrap;" class=" list-paddingleft-2"><li><p>创建Express应用程序并定义JSONP接口</p></li></ol><p class="" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Ubuntu, "Helvetica Neue", Helvetica, Arial, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei UI", "Microsoft YaHei", "Source Han Sans CN", sans-serif, "Apple Color Emoji", "Segoe UI Emoji"; margin-top: 14px; margin-bottom: 0px; font-size: 15px; line-height: 1.75; color: rgb(5, 7, 59); text-wrap: wrap;">在Express应用程序中，可以通过调用app.get()方法来定义一个GET请求的路由处理程序，并使用res.jsonp()方法返回JSONP格式的数据。例如：</p><pre style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; font-family: SFMono-Regular, Consolas, "Liberation Mono", Menlo, Courier, monospace; margin-top: 14px; margin-bottom: 0px; font-size: 15px; overflow: auto; border-radius: 6px; color: rgb(5, 7, 59);"><code class="language-javascript" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; font-family: SFMono-Regular, Consolas, "Liberation Mono", Menlo, Courier, monospace; margin: 0px; font-size: 1em; tab-size: 4;"><table class="hljs hljs-ln"><tbody style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;" class="firstRow"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><span class="hljs-keyword" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(121, 40, 161); line-height: 24px;">const</span> express = <span class="hljs-built_in" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(170, 93, 0); line-height: 24px;">require</span>(<span class="hljs-string" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: green; line-height: 24px;">'express'</span>);</td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><span class="hljs-keyword" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(121, 40, 161); line-height: 24px;">const</span> app = <span class="hljs-title function_" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(0, 127, 170); line-height: 24px;">express</span>();</td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><br/></td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;">app.<span class="hljs-title function_" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(0, 127, 170); line-height: 24px;">get</span>(<span class="hljs-string" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: green; line-height: 24px;">'/data'</span>, <span class="hljs-keyword" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(121, 40, 161); line-height: 24px;">function</span> (<span class="hljs-params" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(170, 93, 0); line-height: 24px;">req, res</span>) {</td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><span class="hljs-keyword" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(121, 40, 161); line-height: 24px;">const</span> data = { <span class="hljs-attr" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;">name</span>: <span class="hljs-string" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: green; line-height: 24px;">'John'</span>, <span class="hljs-attr" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;">age</span>: <span class="hljs-number" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(170, 93, 0); line-height: 24px;">30</span> };</td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;">res.<span class="hljs-title function_" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(0, 127, 170); line-height: 24px;">jsonp</span>(data);</td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;">});</td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><br/></td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;">app.<span class="hljs-title function_" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(0, 127, 170); line-height: 24px;">listen</span>(<span class="hljs-number" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(170, 93, 0); line-height: 24px;">3000</span>, <span class="hljs-keyword" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(121, 40, 161); line-height: 24px;">function</span> (<span class="hljs-params" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(170, 93, 0); line-height: 24px;"></span>) {</td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><span class="hljs-variable language_" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(217, 30, 24); line-height: 24px;">console</span>.<span class="hljs-title function_" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(0, 127, 170); line-height: 24px;">log</span>(<span class="hljs-string" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: green; line-height: 24px;">'Server started on port 3000'</span>);</td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;">});</td></tr></tbody></table></code></pre><p class="" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Ubuntu, "Helvetica Neue", Helvetica, Arial, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei UI", "Microsoft YaHei", "Source Han Sans CN", sans-serif, "Apple Color Emoji", "Segoe UI Emoji"; margin-top: 14px; margin-bottom: 0px; font-size: 15px; line-height: 1.75; color: rgb(5, 7, 59); text-wrap: wrap;">在上面的代码中，我们定义了一个名为/data的路由，当客户端发送GET请求到该路由时，服务器将返回一个JSONP格式的数据。使用res.jsonp()方法返回的数据将会自动添加回调函数名，例如：</p><pre style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; font-family: SFMono-Regular, Consolas, "Liberation Mono", Menlo, Courier, monospace; margin-top: 14px; margin-bottom: 0px; font-size: 15px; overflow: auto; border-radius: 6px; color: rgb(5, 7, 59);"><code class="language-javascript" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; font-family: SFMono-Regular, Consolas, "Liberation Mono", Menlo, Courier, monospace; margin: 0px; font-size: 1em; tab-size: 4;"><table class="hljs hljs-ln"><tbody style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;" class="firstRow"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><span class="hljs-keyword" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(121, 40, 161); line-height: 24px;">const</span> callback = req.<span class="hljs-property" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;">query</span>.<span class="hljs-property" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;">callback</span>;</td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><span class="hljs-keyword" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(121, 40, 161); line-height: 24px;">const</span> data = { <span class="hljs-attr" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;">name</span>: <span class="hljs-string" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: green; line-height: 24px;">'John'</span>, <span class="hljs-attr" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;">age</span>: <span class="hljs-number" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(170, 93, 0); line-height: 24px;">30</span> };</td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;">res.<span class="hljs-title function_" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(0, 127, 170); line-height: 24px;">jsonp</span>(data); <span class="hljs-comment" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(105, 105, 105); line-height: 24px;">// 返回带有callback函数的JSONP数据</span></td></tr></tbody></table></code></pre><p class="" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Ubuntu, "Helvetica Neue", Helvetica, Arial, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei UI", "Microsoft YaHei", "Source Han Sans CN", sans-serif, "Apple Color Emoji", "Segoe UI Emoji"; margin-top: 14px; margin-bottom: 0px; font-size: 15px; line-height: 1.75; color: rgb(5, 7, 59); text-wrap: wrap;">在客户端中，可以使用script标签来请求该路由，并在回调函数中处理返回的数据。例如：</p><pre style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; font-family: SFMono-Regular, Consolas, "Liberation Mono", Menlo, Courier, monospace; margin-top: 14px; margin-bottom: 0px; font-size: 15px; overflow: auto; border-radius: 6px; color: rgb(5, 7, 59);"><code class="language-html" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; font-family: SFMono-Regular, Consolas, "Liberation Mono", Menlo, Courier, monospace; margin: 0px; font-size: 1em; tab-size: 4;"><table class="hljs hljs-ln"><tbody style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;" class="firstRow"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><span class="hljs-tag" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(217, 30, 24); line-height: 24px;"><<span class="hljs-name" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;">script</span>></span><span class="language-javascript" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"> </span></td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><span class="hljs-keyword" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(121, 40, 161); line-height: 24px;">const</span> callback = <span class="hljs-string" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: green; line-height: 24px;">'processData'</span>;</td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><span class="hljs-keyword" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(121, 40, 161); line-height: 24px;">const</span> url = <span class="hljs-string" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: green; line-height: 24px;">'/data?callback='</span> + <span class="hljs-built_in" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(170, 93, 0); line-height: 24px;">encodeURIComponent</span>(callback);</td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><span class="hljs-keyword" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(121, 40, 161); line-height: 24px;">const</span> script = <span class="hljs-variable language_" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(217, 30, 24); line-height: 24px;">document</span>.<span class="hljs-title function_" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(0, 127, 170); line-height: 24px;">createElement</span>(<span class="hljs-string" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: green; line-height: 24px;">'script'</span>);</td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;">script.<span class="hljs-property" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;">src</span> = url;</td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><span class="hljs-variable language_" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(217, 30, 24); line-height: 24px;">document</span>.<span class="hljs-property" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;">head</span>.<span class="hljs-title function_" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(0, 127, 170); line-height: 24px;">appendChild</span>(script);</td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><span class="hljs-tag" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(217, 30, 24); line-height: 24px;"></<span class="hljs-name" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;">script</span>></span></td></tr></tbody></table></code></pre><p><br/></p>
<p class="" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Ubuntu, "Helvetica Neue", Helvetica, Arial, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei UI", "Microsoft YaHei", "Source Han Sans CN", sans-serif, "Apple Color Emoji", "Segoe UI Emoji"; margin-top: 0px; margin-bottom: 0px; font-size: 15px; line-height: 1.75; color: rgb(5, 7, 59); text-wrap: wrap;">在Node.js中，接口跨域是指在不同域名之间进行数据交互时，由于浏览器的同源策略限制，导致无法直接访问其他域名下的接口。为了解决这个问题，可以采用以下几种方式：</p><ol style="box-sizing: border-box; padding: 0px 0px 0px 32px; -webkit-font-smoothing: antialiased; list-style-position: outside; list-style-image: none; font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Ubuntu, "Helvetica Neue", Helvetica, Arial, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei UI", "Microsoft YaHei", "Source Han Sans CN", sans-serif, "Apple Color Emoji", "Segoe UI Emoji"; margin-top: 14px; margin-bottom: 1em; font-size: 15px; line-height: 1.75; color: rgb(5, 7, 59); text-wrap: wrap;" class=" list-paddingleft-2"><li><p>JSONP<br/>JSONP是一种通过动态添加script标签来请求跨域数据的技术，它可以在服务器端返回JavaScript代码，然后在客户端执行该代码以获取数据。在Node.js中，可以使用Express框架的res.jsonp()方法来返回JSONP格式的数据。</p></li><li><p>CORS<br/>CORS（跨源资源共享）是一种标准化的跨域解决方案，它通过服务器端设置HTTP头信息来实现跨域访问。在Node.js中，可以使用cors模块来实现CORS功能。</p></li><li><p>代理服务器<br/>代理服务器是一种将请求转发到另一个服务器的方法，它可以解决跨域问题。在Node.js中，可以使用http-proxy-middleware模块来实现代理服务器功能。</p></li></ol><p class="" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Ubuntu, "Helvetica Neue", Helvetica, Arial, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei UI", "Microsoft YaHei", "Source Han Sans CN", sans-serif, "Apple Color Emoji", "Segoe UI Emoji"; margin-top: 14px; margin-bottom: 0px; font-size: 15px; line-height: 1.75; color: rgb(5, 7, 59); text-wrap: wrap;">下面是一个使用cors模块实现CORS功能的示例代码：</p><ol style="box-sizing: border-box; padding: 0px 0px 0px 32px; -webkit-font-smoothing: antialiased; list-style-position: outside; list-style-image: none; font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Ubuntu, "Helvetica Neue", Helvetica, Arial, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei UI", "Microsoft YaHei", "Source Han Sans CN", sans-serif, "Apple Color Emoji", "Segoe UI Emoji"; margin-top: 14px; margin-bottom: 1em; font-size: 15px; line-height: 1.75; color: rgb(5, 7, 59); text-wrap: wrap;" class=" list-paddingleft-2"><li><p>安装cors模块</p></li></ol><p class="" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Ubuntu, "Helvetica Neue", Helvetica, Arial, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei UI", "Microsoft YaHei", "Source Han Sans CN", sans-serif, "Apple Color Emoji", "Segoe UI Emoji"; margin-top: 14px; margin-bottom: 0px; font-size: 15px; line-height: 1.75; color: rgb(5, 7, 59); text-wrap: wrap;">首先，需要在Node.js项目中安装cors模块，可以通过npm进行安装：</p><pre style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; font-family: SFMono-Regular, Consolas, "Liberation Mono", Menlo, Courier, monospace; margin-top: 14px; margin-bottom: 0px; font-size: 15px; overflow: auto; border-radius: 6px; color: rgb(5, 7, 59);"><code class="language-shell" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; font-family: SFMono-Regular, Consolas, "Liberation Mono", Menlo, Courier, monospace; margin: 0px; font-size: 1em; tab-size: 4;"><table class="hljs hljs-ln"><tbody style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;" class="firstRow"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;">npm install cors</td></tr></tbody></table></code></pre><ol style="box-sizing: border-box; padding: 0px 0px 0px 32px; -webkit-font-smoothing: antialiased; list-style-position: outside; list-style-image: none; font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Ubuntu, "Helvetica Neue", Helvetica, Arial, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei UI", "Microsoft YaHei", "Source Han Sans CN", sans-serif, "Apple Color Emoji", "Segoe UI Emoji"; margin-top: 14px; margin-bottom: 1em; font-size: 15px; line-height: 1.75; color: rgb(5, 7, 59); text-wrap: wrap;" class=" list-paddingleft-2"><li><p>创建Express应用程序并启用CORS功能</p></li></ol><p class="" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Ubuntu, "Helvetica Neue", Helvetica, Arial, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei UI", "Microsoft YaHei", "Source Han Sans CN", sans-serif, "Apple Color Emoji", "Segoe UI Emoji"; margin-top: 14px; margin-bottom: 0px; font-size: 15px; line-height: 1.75; color: rgb(5, 7, 59); text-wrap: wrap;">在Express应用程序中，可以通过调用app.use()方法来启用CORS功能。例如：</p><pre style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; font-family: SFMono-Regular, Consolas, "Liberation Mono", Menlo, Courier, monospace; margin-top: 14px; margin-bottom: 0px; font-size: 15px; overflow: auto; border-radius: 6px; color: rgb(5, 7, 59);"><code class="language-javascript" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; font-family: SFMono-Regular, Consolas, "Liberation Mono", Menlo, Courier, monospace; margin: 0px; font-size: 1em; tab-size: 4;"><table class="hljs hljs-ln"><tbody style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;" class="firstRow"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><span class="hljs-keyword" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(121, 40, 161); line-height: 24px;">const</span> express = <span class="hljs-built_in" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(170, 93, 0); line-height: 24px;">require</span>(<span class="hljs-string" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: green; line-height: 24px;">'express'</span>);</td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><span class="hljs-keyword" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(121, 40, 161); line-height: 24px;">const</span> cors = <span class="hljs-built_in" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(170, 93, 0); line-height: 24px;">require</span>(<span class="hljs-string" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: green; line-height: 24px;">'cors'</span>);</td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><span class="hljs-keyword" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(121, 40, 161); line-height: 24px;">const</span> app = <span class="hljs-title function_" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(0, 127, 170); line-height: 24px;">express</span>();</td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><br/></td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;">app.<span class="hljs-title function_" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(0, 127, 170); line-height: 24px;">use</span>(<span class="hljs-title function_" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(0, 127, 170); line-height: 24px;">cors</span>());</td></tr></tbody></table></code></pre><p class="" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Ubuntu, "Helvetica Neue", Helvetica, Arial, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei UI", "Microsoft YaHei", "Source Han Sans CN", sans-serif, "Apple Color Emoji", "Segoe UI Emoji"; margin-top: 14px; margin-bottom: 0px; font-size: 15px; line-height: 1.75; color: rgb(5, 7, 59); text-wrap: wrap;">这样就可以在客户端中跨域访问该应用程序下的接口了。</p><p><br/></p>
<p class="" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Ubuntu, "Helvetica Neue", Helvetica, Arial, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei UI", "Microsoft YaHei", "Source Han Sans CN", sans-serif, "Apple Color Emoji", "Segoe UI Emoji"; margin-top: 0px; margin-bottom: 0px; font-size: 15px; line-height: 1.75; color: rgb(5, 7, 59); text-wrap: wrap;">在Node.js中，可以使用Express框架来编写接口。Express是一个基于Node.js的轻量级Web应用程序框架，它提供了一系列的中间件和路由处理程序来处理HTTP请求和响应。下面是一个使用Express框架编写接口的示例代码：</p><p>安装Express模块</p><p class="" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Ubuntu, "Helvetica Neue", Helvetica, Arial, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei UI", "Microsoft YaHei", "Source Han Sans CN", sans-serif, "Apple Color Emoji", "Segoe UI Emoji"; margin-top: 14px; margin-bottom: 0px; font-size: 15px; line-height: 1.75; color: rgb(5, 7, 59); text-wrap: wrap;">首先，需要在Node.js项目中安装Express模块，可以通过npm进行安装：</p><pre style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; font-family: SFMono-Regular, Consolas, "Liberation Mono", Menlo, Courier, monospace; margin-top: 14px; margin-bottom: 0px; font-size: 15px; overflow: auto; border-radius: 6px; color: rgb(5, 7, 59);"><code class="language-shell" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; font-family: SFMono-Regular, Consolas, "Liberation Mono", Menlo, Courier, monospace; margin: 0px; font-size: 1em; tab-size: 4;"><table class="hljs hljs-ln"><tbody style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;" class="firstRow"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;">npm install express</td></tr></tbody></table></code></pre><p>创建Express应用程序并定义路由处理程序</p><p class="" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Ubuntu, "Helvetica Neue", Helvetica, Arial, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei UI", "Microsoft YaHei", "Source Han Sans CN", sans-serif, "Apple Color Emoji", "Segoe UI Emoji"; margin-top: 14px; margin-bottom: 0px; font-size: 15px; line-height: 1.75; color: rgb(5, 7, 59); text-wrap: wrap;">在Express应用程序中，可以使用app.get()、app.post()、app.put()等方法来定义路由处理程序。例如：</p><pre style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; font-family: SFMono-Regular, Consolas, "Liberation Mono", Menlo, Courier, monospace; margin-top: 14px; margin-bottom: 0px; font-size: 15px; overflow: auto; border-radius: 6px; color: rgb(5, 7, 59);"><code class="language-javascript" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; font-family: SFMono-Regular, Consolas, "Liberation Mono", Menlo, Courier, monospace; margin: 0px; font-size: 1em; tab-size: 4;"><table class="hljs hljs-ln"><tbody style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;" class="firstRow"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><span class="hljs-keyword" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(121, 40, 161); line-height: 24px;">const</span> express = <span class="hljs-built_in" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(170, 93, 0); line-height: 24px;">require</span>(<span class="hljs-string" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: green; line-height: 24px;">'express'</span>);</td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><span class="hljs-keyword" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(121, 40, 161); line-height: 24px;">const</span> app = <span class="hljs-title function_" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(0, 127, 170); line-height: 24px;">express</span>();</td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><br/></td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;">app.<span class="hljs-title function_" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(0, 127, 170); line-height: 24px;">get</span>(<span class="hljs-string" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: green; line-height: 24px;">'/users'</span>, <span class="hljs-keyword" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(121, 40, 161); line-height: 24px;">function</span> (<span class="hljs-params" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(170, 93, 0); line-height: 24px;">req, res</span>) {</td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><span class="hljs-keyword" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(121, 40, 161); line-height: 24px;">const</span> users = [</td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;">{ <span class="hljs-attr" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;">id</span>: <span class="hljs-number" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(170, 93, 0); line-height: 24px;">1</span>, <span class="hljs-attr" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;">name</span>: <span class="hljs-string" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: green; line-height: 24px;">'John'</span>, <span class="hljs-attr" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;">age</span>: <span class="hljs-number" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(170, 93, 0); line-height: 24px;">25</span> },</td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;">{ <span class="hljs-attr" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;">id</span>: <span class="hljs-number" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(170, 93, 0); line-height: 24px;">2</span>, <span class="hljs-attr" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;">name</span>: <span class="hljs-string" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: green; line-height: 24px;">'Mary'</span>, <span class="hljs-attr" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;">age</span>: <span class="hljs-number" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(170, 93, 0); line-height: 24px;">30</span> },</td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;">{ <span class="hljs-attr" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;">id</span>: <span class="hljs-number" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(170, 93, 0); line-height: 24px;">3</span>, <span class="hljs-attr" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;">name</span>: <span class="hljs-string" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: green; line-height: 24px;">'Bob'</span>, <span class="hljs-attr" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;">age</span>: <span class="hljs-number" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(170, 93, 0); line-height: 24px;">35</span> }</td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;">];</td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;">res.<span class="hljs-title function_" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(0, 127, 170); line-height: 24px;">json</span>(users);</td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;">});</td></tr></tbody></table></code></pre><p class="" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Ubuntu, "Helvetica Neue", Helvetica, Arial, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei UI", "Microsoft YaHei", "Source Han Sans CN", sans-serif, "Apple Color Emoji", "Segoe UI Emoji"; margin-top: 14px; margin-bottom: 0px; font-size: 15px; line-height: 1.75; color: rgb(5, 7, 59); text-wrap: wrap;">在上面的代码中，我们定义了一个名为/users的路由，当客户端发送GET请求到该路由时，服务器将返回一个包含用户数据的JSON格式数据。使用res.json()方法返回的数据将会自动转换成JSON格式。<br/>添加中间件</p><p class="" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Ubuntu, "Helvetica Neue", Helvetica, Arial, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei UI", "Microsoft YaHei", "Source Han Sans CN", sans-serif, "Apple Color Emoji", "Segoe UI Emoji"; margin-top: 14px; margin-bottom: 0px; font-size: 15px; line-height: 1.75; color: rgb(5, 7, 59); text-wrap: wrap;">Express框架提供了一系列的中间件来处理HTTP请求和响应。例如，可以使用body-parser中间件来解析POST请求中的数据。下面是一个使用body-parser中间件的示例代码：</p><pre style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; font-family: SFMono-Regular, Consolas, "Liberation Mono", Menlo, Courier, monospace; margin-top: 14px; margin-bottom: 0px; font-size: 15px; overflow: auto; border-radius: 6px; color: rgb(5, 7, 59);"><code class="language-javascript" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; font-family: SFMono-Regular, Consolas, "Liberation Mono", Menlo, Courier, monospace; margin: 0px; font-size: 1em; tab-size: 4;"><table class="hljs hljs-ln"><tbody style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;" class="firstRow"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><span class="hljs-keyword" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(121, 40, 161); line-height: 24px;">const</span> express = <span class="hljs-built_in" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(170, 93, 0); line-height: 24px;">require</span>(<span class="hljs-string" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: green; line-height: 24px;">'express'</span>);</td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><span class="hljs-keyword" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(121, 40, 161); line-height: 24px;">const</span> bodyParser = <span class="hljs-built_in" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(170, 93, 0); line-height: 24px;">require</span>(<span class="hljs-string" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: green; line-height: 24px;">'body-parser'</span>);</td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><span class="hljs-keyword" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(121, 40, 161); line-height: 24px;">const</span> app = <span class="hljs-title function_" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(0, 127, 170); line-height: 24px;">express</span>();</td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><br/></td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;">app.<span class="hljs-title function_" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(0, 127, 170); line-height: 24px;">use</span>(bodyParser.<span class="hljs-title function_" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(0, 127, 170); line-height: 24px;">json</span>()); <span class="hljs-comment" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(105, 105, 105); line-height: 24px;">// 解析JSON格式的POST请求数据 </span></td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;">app.<span class="hljs-title function_" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(0, 127, 170); line-height: 24px;">use</span>(bodyParser.<span class="hljs-title function_" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(0, 127, 170); line-height: 24px;">urlencoded</span>({ <span class="hljs-attr" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;">extended</span>: <span class="hljs-literal" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(170, 93, 0); line-height: 24px;">true</span> })); <span class="hljs-comment" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(105, 105, 105); line-height: 24px;">// 解析URL编码的POST请求数据</span></td></tr></tbody></table></code></pre><p>处理异常</p><p class="" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Ubuntu, "Helvetica Neue", Helvetica, Arial, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei UI", "Microsoft YaHei", "Source Han Sans CN", sans-serif, "Apple Color Emoji", "Segoe UI Emoji"; margin-top: 14px; margin-bottom: 0px; font-size: 15px; line-height: 1.75; color: rgb(5, 7, 59); text-wrap: wrap;">在Express应用程序中，可以使用app.use()方法来捕获全局异常，并在异常处理程序中进行统一处理。例如：</p><pre style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; font-family: SFMono-Regular, Consolas, "Liberation Mono", Menlo, Courier, monospace; margin-top: 14px; margin-bottom: 0px; font-size: 15px; overflow: auto; border-radius: 6px; color: rgb(5, 7, 59);"><code class="language-javascript" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; font-family: SFMono-Regular, Consolas, "Liberation Mono", Menlo, Courier, monospace; margin: 0px; font-size: 1em; tab-size: 4;"><table class="hljs hljs-ln"><tbody style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;" class="firstRow"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><span class="hljs-keyword" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(121, 40, 161); line-height: 24px;">const</span> express = <span class="hljs-built_in" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(170, 93, 0); line-height: 24px;">require</span>(<span class="hljs-string" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: green; line-height: 24px;">'express'</span>);</td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><span class="hljs-keyword" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(121, 40, 161); line-height: 24px;">const</span> app = <span class="hljs-title function_" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(0, 127, 170); line-height: 24px;">express</span>();</td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><br/></td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;">app.<span class="hljs-title function_" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(0, 127, 170); line-height: 24px;">use</span>(<span class="hljs-function" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;">(<span class="hljs-params" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(170, 93, 0); line-height: 24px;">err, req, res, next</span>) =></span> {</td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><span class="hljs-variable language_" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(217, 30, 24); line-height: 24px;">console</span>.<span class="hljs-title function_" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(0, 127, 170); line-height: 24px;">error</span>(err); <span class="hljs-comment" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(105, 105, 105); line-height: 24px;">// 输出异常信息到日志中 </span></td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;">res.<span class="hljs-title function_" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(0, 127, 170); line-height: 24px;">status</span>(<span class="hljs-number" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(170, 93, 0); line-height: 24px;">500</span>).<span class="hljs-title function_" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(0, 127, 170); line-height: 24px;">send</span>(<span class="hljs-string" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: green; line-height: 24px;">'Server Error'</span>); <span class="hljs-comment" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(105, 105, 105); line-height: 24px;">// 返回500错误码和错误信息给客户端 </span></td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;">});</td></tr></tbody></table></code><br/><br/></pre><pre style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; font-family: SFMono-Regular, Consolas, "Liberation Mono", Menlo, Courier, monospace; margin-top: 14px; margin-bottom: 0px; font-size: 15px; overflow: auto; border-radius: 6px; color: rgb(5, 7, 59);">启动应用程序并监听端口</pre><p>最后，可以使用app.listen()方法来启动应用程序并监听端口。例如：</p><pre style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; font-family: SFMono-Regular, Consolas, "Liberation Mono", Menlo, Courier, monospace; margin-top: 14px; margin-bottom: 0px; font-size: 15px; overflow: auto; border-radius: 6px; color: rgb(5, 7, 59);"><code class="language-javascript" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; font-family: SFMono-Regular, Consolas, "Liberation Mono", Menlo, Courier, monospace; margin: 0px; font-size: 1em; tab-size: 4;"><table class="hljs hljs-ln"><tbody style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;" class="firstRow"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><span class="hljs-keyword" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(121, 40, 161); line-height: 24px;">const</span> express = <span class="hljs-built_in" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(170, 93, 0); line-height: 24px;">require</span>(<span class="hljs-string" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: green; line-height: 24px;">'express'</span>);</td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><span class="hljs-keyword" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(121, 40, 161); line-height: 24px;">const</span> app = <span class="hljs-title function_" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(0, 127, 170); line-height: 24px;">express</span>();</td></tr></tbody></table></code></pre><p><br/></p>
<p class="" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Ubuntu, "Helvetica Neue", Helvetica, Arial, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei UI", "Microsoft YaHei", "Source Han Sans CN", sans-serif, "Apple Color Emoji", "Segoe UI Emoji"; margin-top: 0px; margin-bottom: 0px; font-size: 15px; line-height: 1.75; color: rgb(5, 7, 59); text-wrap: wrap;">在Node.js中，Express框架本身并没有太多功能，而其大多功能都是通过中间件实现的。中间件本质上是一个处理函数，它接收请求对象（req）、响应对象（res）和下一个中间件作为参数。一个请求所匹配的中间件函数中所有的request和response都是同一个对象。</p><p class="" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Ubuntu, "Helvetica Neue", Helvetica, Arial, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei UI", "Microsoft YaHei", "Source Han Sans CN", sans-serif, "Apple Color Emoji", "Segoe UI Emoji"; margin-top: 14px; margin-bottom: 0px; font-size: 15px; line-height: 1.75; color: rgb(5, 7, 59); text-wrap: wrap;">在Express中，有一些内置的中间件，其中一些包括：</p><ol style="box-sizing: border-box; padding: 0px 0px 0px 32px; -webkit-font-smoothing: antialiased; list-style-position: outside; list-style-image: none; font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Ubuntu, "Helvetica Neue", Helvetica, Arial, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei UI", "Microsoft YaHei", "Source Han Sans CN", sans-serif, "Apple Color Emoji", "Segoe UI Emoji"; margin-top: 14px; margin-bottom: 1em; font-size: 15px; line-height: 1.75; color: rgb(5, 7, 59); text-wrap: wrap;" class=" list-paddingleft-2"><li><p>错误处理中间件：这类中间件是全局的，可以捕获在处理请求时发生的任何错误。在Express中，可以使用app.use()方法注册一个错误处理中间件，它会在所有的路由和中间件处理程序执行完毕后执行。</p></li><li><p>静态资源服务中间件：Express提供了一个内置的中间件来处理静态资源服务，它可以将静态文件映射到HTTP请求中。例如，可以使用app.use()方法将静态文件目录映射到特定的URL路径上。</p></li><li><p>路由中间件：路由中间件用于处理特定URL路径的请求。在Express中，可以使用app.get()、app.post()、app.put()等方法来定义路由处理程序，这些方法都接受一个URL路径和一个回调函数作为参数。</p></li><li><p>格式化响应数据的中间件：这类中间件可以在响应对象上添加额外的属性和方法，从而改变响应数据的格式。例如，可以使用res.json()方法将JSON格式的数据发送给客户端。</p></li><li><p>身份验证和授权中间件：这类中间件可以用于验证客户端的身份和授权，从而限制对特定路由的访问权限。例如，可以使用Passport.js等第三方库来实现身份验证和授权功能。</p></li></ol><p class="" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Ubuntu, "Helvetica Neue", Helvetica, Arial, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei UI", "Microsoft YaHei", "Source Han Sans CN", sans-serif, "Apple Color Emoji", "Segoe UI Emoji"; margin-top: 14px; margin-bottom: 0px; font-size: 15px; line-height: 1.75; color: rgb(5, 7, 59); text-wrap: wrap;">总的来说，Express的内置中间件提供了许多常用的功能和工具，以帮助开发人员快速构建和扩展Web应用程序。</p><p><br/></p>
<p class="" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Ubuntu, "Helvetica Neue", Helvetica, Arial, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei UI", "Microsoft YaHei", "Source Han Sans CN", sans-serif, "Apple Color Emoji", "Segoe UI Emoji"; margin-top: 0px; margin-bottom: 0px; font-size: 15px; line-height: 1.75; color: rgb(5, 7, 59); text-wrap: wrap;">在Node.js中，中间件是一个非常重要的概念，它主要用于处理HTTP请求和响应。中间件本质上是一个函数，它接收请求对象（req）、响应对象（res）和下一个中间件作为参数。通过使用中间件，我们可以执行各种任务，例如身份验证、授权、日志记录、错误处理等。</p><p class="" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Ubuntu, "Helvetica Neue", Helvetica, Arial, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei UI", "Microsoft YaHei", "Source Han Sans CN", sans-serif, "Apple Color Emoji", "Segoe UI Emoji"; margin-top: 14px; margin-bottom: 0px; font-size: 15px; line-height: 1.75; color: rgb(5, 7, 59); text-wrap: wrap;">根据不同的应用场景和调用方式，中间件可以分为以下几个类别：</p><ol style="box-sizing: border-box; padding: 0px 0px 0px 32px; -webkit-font-smoothing: antialiased; list-style-position: outside; list-style-image: none; font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Ubuntu, "Helvetica Neue", Helvetica, Arial, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei UI", "Microsoft YaHei", "Source Han Sans CN", sans-serif, "Apple Color Emoji", "Segoe UI Emoji"; margin-top: 14px; margin-bottom: 1em; font-size: 15px; line-height: 1.75; color: rgb(5, 7, 59); text-wrap: wrap;" class=" list-paddingleft-2"><li><p>应用程序级别的中间件：这种类型的中间件是针对应用程序的特定功能或需求而开发的。例如，一些应用程序可能需要处理敏感信息，如用户身份验证和授权，这时可以使用应用程序级别的中间件来处理这些信息。</p></li><li><p>路由级别的中间件：这种类型的中间件是针对特定的路由路径而开发的。例如，当用户访问特定URL路径时，可以使用路由级别的中间件来验证用户的身份或处理特定的业务逻辑。</p></li><li><p>错误处理中间件：这种类型的中间件用于处理HTTP请求中发生的错误。在Express中，可以使用app.use()方法注册一个错误处理中间件，它会在所有的路由和中间件处理程序执行完毕后执行。</p></li><li><p>内置中间件：Express框架本身提供了一些内置的中间件，例如格式化响应数据的中间件、静态资源服务中间件等。这些中间件可以满足一些基本的开发需求，而无需开发人员自己编写代码。</p></li><li><p>第三方中间件：这种类型的中间件是由第三方开发的，可以提供更丰富的功能和更灵活的解决方案。例如，可以使用第三方中间件来实现日志记录、数据校验等功能。</p></li></ol><p class="" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Ubuntu, "Helvetica Neue", Helvetica, Arial, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei UI", "Microsoft YaHei", "Source Han Sans CN", sans-serif, "Apple Color Emoji", "Segoe UI Emoji"; margin-top: 14px; margin-bottom: 0px; font-size: 15px; line-height: 1.75; color: rgb(5, 7, 59); text-wrap: wrap;">以上是Node.js中常见的中间件分类，不同的中间件可以实现不同的功能和需求，开发人员可以根据具体的应用场景和需求选择合适的中间件来使用。</p><p><br/></p>
<p class="" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Ubuntu, "Helvetica Neue", Helvetica, Arial, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei UI", "Microsoft YaHei", "Source Han Sans CN", sans-serif, "Apple Color Emoji", "Segoe UI Emoji"; margin-top: 0px; margin-bottom: 0px; font-size: 15px; line-height: 1.75; color: rgb(5, 7, 59); text-wrap: wrap;">在 Node.js 的 Express 框架中，中间件是一个非常重要的概念。它是一种在 HTTP 请求和响应循环中执行特定任务的方法。这些任务可以包括处理身份验证、会话管理、数据解析和路由等。中间件可以访问请求对象、响应对象，以及在请求和响应之间进行转换的下一个中间件。</p><p class="" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Ubuntu, "Helvetica Neue", Helvetica, Arial, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei UI", "Microsoft YaHei", "Source Han Sans CN", sans-serif, "Apple Color Emoji", "Segoe UI Emoji"; margin-top: 14px; margin-bottom: 0px; font-size: 15px; line-height: 1.75; color: rgb(5, 7, 59); text-wrap: wrap;">在 Express 中，中间件可以全局注册，也可以局部注册。全局中间件适用于应用程序中的所有路由，而局部中间件则仅适用于特定的路由。</p><p class="" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Ubuntu, "Helvetica Neue", Helvetica, Arial, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei UI", "Microsoft YaHei", "Source Han Sans CN", sans-serif, "Apple Color Emoji", "Segoe UI Emoji"; margin-top: 14px; margin-bottom: 0px; font-size: 15px; line-height: 1.75; color: rgb(5, 7, 59); text-wrap: wrap;">下面是一个局部中间件的例子：</p><pre style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; font-family: SFMono-Regular, Consolas, "Liberation Mono", Menlo, Courier, monospace; margin-top: 14px; margin-bottom: 0px; font-size: 15px; overflow: auto; border-radius: 6px; color: rgb(5, 7, 59);"><code class="language-javascript" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; font-family: SFMono-Regular, Consolas, "Liberation Mono", Menlo, Courier, monospace; margin: 0px; font-size: 1em; tab-size: 4;"><table class="hljs hljs-ln"><tbody style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;" class="firstRow"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;">app.<span class="hljs-title function_" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(0, 127, 170); line-height: 24px;">get</span>(<span class="hljs-string" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: green; line-height: 24px;">'/example'</span>, <span class="hljs-keyword" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(121, 40, 161); line-height: 24px;">function</span>(<span class="hljs-params" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(170, 93, 0); line-height: 24px;">req, res, next</span>) {</td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><span class="hljs-comment" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(105, 105, 105); line-height: 24px;">// 这个函数就是一个中间件函数 </span></td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><span class="hljs-variable language_" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(217, 30, 24); line-height: 24px;">console</span>.<span class="hljs-title function_" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(0, 127, 170); line-height: 24px;">log</span>(<span class="hljs-string" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: green; line-height: 24px;">'This is a middleware function.'</span>);</td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><span class="hljs-title function_" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(0, 127, 170); line-height: 24px;">next</span>(); <span class="hljs-comment" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(105, 105, 105); line-height: 24px;">// 调用 next 函数以进行下一个中间件或路由处理程序 </span></td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;">}, <span class="hljs-keyword" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(121, 40, 161); line-height: 24px;">function</span>(<span class="hljs-params" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(170, 93, 0); line-height: 24px;">req, res</span>) {</td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><span class="hljs-comment" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(105, 105, 105); line-height: 24px;">// 这个函数是一个路由处理程序 </span></td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;">res.<span class="hljs-title function_" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(0, 127, 170); line-height: 24px;">send</span>(<span class="hljs-string" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: green; line-height: 24px;">'This is a route handler.'</span>);</td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;">});</td></tr></tbody></table></code></pre><p class="" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Ubuntu, "Helvetica Neue", Helvetica, Arial, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei UI", "Microsoft YaHei", "Source Han Sans CN", sans-serif, "Apple Color Emoji", "Segoe UI Emoji"; margin-top: 14px; margin-bottom: 0px; font-size: 15px; line-height: 1.75; color: rgb(5, 7, 59); text-wrap: wrap;">在这个例子中，我们定义了一个 GET 路由 '/example'。这个路由有两个处理程序：一个中间件函数和一个路由处理程序。中间件函数首先被调用，然后是路由处理程序。</p><p class="" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Ubuntu, "Helvetica Neue", Helvetica, Arial, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei UI", "Microsoft YaHei", "Source Han Sans CN", sans-serif, "Apple Color Emoji", "Segoe UI Emoji"; margin-top: 14px; margin-bottom: 0px; font-size: 15px; line-height: 1.75; color: rgb(5, 7, 59); text-wrap: wrap;">局部中间件与全局中间件的主要区别在于它们的作用范围。局部中间件仅在特定的路由处理程序中执行，而全局中间件则在所有路由处理程序中执行。</p><p class="" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Ubuntu, "Helvetica Neue", Helvetica, Arial, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei UI", "Microsoft YaHei", "Source Han Sans CN", sans-serif, "Apple Color Emoji", "Segoe UI Emoji"; margin-top: 14px; margin-bottom: 0px; font-size: 15px; line-height: 1.75; color: rgb(5, 7, 59); text-wrap: wrap;">在 Node.js 的 Express 框架中，我们可以使用任何数量的中间件来处理 HTTP 请求。中间件可以用于执行各种任务，例如验证用户身份、检查用户会话状态、解析请求数据等。</p><p><br/></p>
<p class="" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Ubuntu, "Helvetica Neue", Helvetica, Arial, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei UI", "Microsoft YaHei", "Source Han Sans CN", sans-serif, "Apple Color Emoji", "Segoe UI Emoji"; margin-top: 0px; margin-bottom: 0px; font-size: 15px; line-height: 1.75; color: rgb(5, 7, 59); text-wrap: wrap;">在 Node.js 中，可以使用 <code class=" inline" style="box-sizing: border-box; padding: 1px 4px; -webkit-font-smoothing: antialiased; list-style: none; font-family: SFMono-Regular, Consolas, "Liberation Mono", Menlo, Courier, monospace; margin: 0px 2px; font-size: 12.75px; tab-size: 4; background-color: rgba(27, 31, 35, 0.05); border-radius: 3px;">app.use()</code> 函数定义多个全局中间件。这些全局中间件会应用于所有路由和传入的请求对象（req）和响应对象（res）。</p><p class="" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Ubuntu, "Helvetica Neue", Helvetica, Arial, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei UI", "Microsoft YaHei", "Source Han Sans CN", sans-serif, "Apple Color Emoji", "Segoe UI Emoji"; margin-top: 14px; margin-bottom: 0px; font-size: 15px; line-height: 1.75; color: rgb(5, 7, 59); text-wrap: wrap;">以下是一个示例，展示如何定义两个全局中间件：</p><pre style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; font-family: SFMono-Regular, Consolas, "Liberation Mono", Menlo, Courier, monospace; margin-top: 14px; margin-bottom: 0px; font-size: 15px; overflow: auto; border-radius: 6px; color: rgb(5, 7, 59);"><code class="language-javascript" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; font-family: SFMono-Regular, Consolas, "Liberation Mono", Menlo, Courier, monospace; margin: 0px; font-size: 1em; tab-size: 4;"><table class="hljs hljs-ln"><tbody style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;" class="firstRow"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><span class="hljs-keyword" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(121, 40, 161); line-height: 24px;">const</span> express = <span class="hljs-built_in" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(170, 93, 0); line-height: 24px;">require</span>(<span class="hljs-string" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: green; line-height: 24px;">'express'</span>);</td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><span class="hljs-keyword" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(121, 40, 161); line-height: 24px;">const</span> app = <span class="hljs-title function_" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(0, 127, 170); line-height: 24px;">express</span>();</td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><br/></td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><span class="hljs-comment" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(105, 105, 105); line-height: 24px;">// 定义第一个全局中间件 </span></td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;">app.<span class="hljs-title function_" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(0, 127, 170); line-height: 24px;">use</span>(<span class="hljs-function" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;">(<span class="hljs-params" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(170, 93, 0); line-height: 24px;">req, res, next</span>) =></span> {</td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><span class="hljs-variable language_" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(217, 30, 24); line-height: 24px;">console</span>.<span class="hljs-title function_" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(0, 127, 170); line-height: 24px;">log</span>(<span class="hljs-string" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: green; line-height: 24px;">'调用了第1个全局中间件'</span>);</td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><span class="hljs-title function_" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(0, 127, 170); line-height: 24px;">next</span>(); <span class="hljs-comment" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(105, 105, 105); line-height: 24px;">// 调用 next 函数以进行下一个中间件或路由处理程序 </span></td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;">});</td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><br/></td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><span class="hljs-comment" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(105, 105, 105); line-height: 24px;">// 定义第二个全局中间件 </span></td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;">app.<span class="hljs-title function_" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(0, 127, 170); line-height: 24px;">use</span>(<span class="hljs-function" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;">(<span class="hljs-params" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(170, 93, 0); line-height: 24px;">req, res, next</span>) =></span> {</td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><span class="hljs-variable language_" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(217, 30, 24); line-height: 24px;">console</span>.<span class="hljs-title function_" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(0, 127, 170); line-height: 24px;">log</span>(<span class="hljs-string" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: green; line-height: 24px;">'调用了第2个全局中间件'</span>);</td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><span class="hljs-title function_" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(0, 127, 170); line-height: 24px;">next</span>(); <span class="hljs-comment" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(105, 105, 105); line-height: 24px;">// 调用 next 函数以进行下一个中间件或路由处理程序 </span></td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;">});</td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><br/></td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><span class="hljs-comment" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(105, 105, 105); line-height: 24px;">// 定义一个路由 </span></td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;">app.<span class="hljs-title function_" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(0, 127, 170); line-height: 24px;">get</span>(<span class="hljs-string" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: green; line-height: 24px;">'/user'</span>, <span class="hljs-function" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;">(<span class="hljs-params" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(170, 93, 0); line-height: 24px;">req, res</span>) =></span> {</td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;">res.<span class="hljs-title function_" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(0, 127, 170); line-height: 24px;">send</span>(<span class="hljs-string" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: green; line-height: 24px;">'User page.'</span>);</td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;">});</td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><br/></td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;">app.<span class="hljs-title function_" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(0, 127, 170); line-height: 24px;">listen</span>(<span class="hljs-number" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(170, 93, 0); line-height: 24px;">80</span>, <span class="hljs-function" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;">() =></span> {</td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><span class="hljs-variable language_" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(217, 30, 24); line-height: 24px;">console</span>.<span class="hljs-title function_" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(0, 127, 170); line-height: 24px;">log</span>(<span class="hljs-string" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: green; line-height: 24px;">'http://127.0.0.1'</span>);</td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;">});</td></tr></tbody></table></code></pre><p class="" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Ubuntu, "Helvetica Neue", Helvetica, Arial, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei UI", "Microsoft YaHei", "Source Han Sans CN", sans-serif, "Apple Color Emoji", "Segoe UI Emoji"; margin-top: 14px; margin-bottom: 0px; font-size: 15px; line-height: 1.75; color: rgb(5, 7, 59); text-wrap: wrap;">在这个示例中，我们使用 <code class=" inline" style="box-sizing: border-box; padding: 1px 4px; -webkit-font-smoothing: antialiased; list-style: none; font-family: SFMono-Regular, Consolas, "Liberation Mono", Menlo, Courier, monospace; margin: 0px 2px; font-size: 12.75px; tab-size: 4; background-color: rgba(27, 31, 35, 0.05); border-radius: 3px;">app.use()</code> 函数连续定义了两个全局中间件。它们都会在每个传入的 HTTP 请求时被调用，并按它们被定义的顺序执行。每个中间件函数都会接收请求对象（req）、响应对象（res）和一个 next 函数作为参数。通过调用 next 函数，我们可以将控制权传递给下一个中间件或路由处理程序。</p><p><br/></p>
<p class="" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Ubuntu, "Helvetica Neue", Helvetica, Arial, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei UI", "Microsoft YaHei", "Source Han Sans CN", sans-serif, "Apple Color Emoji", "Segoe UI Emoji"; margin-top: 0px; margin-bottom: 0px; font-size: 15px; line-height: 1.75; color: rgb(5, 7, 59); text-wrap: wrap;">在 Node.js 中，当有多个中间件函数被注册到同一个路由或应用程序时，请求对象（req）和响应对象（res）会在中间件函数之间共享。这意味着在一个中间件函数中可以对请求对象或响应对象进行修改或添加属性，这些修改或属性可以在后续的中间件函数或路由处理程序中访问和使用。</p><p class="" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Ubuntu, "Helvetica Neue", Helvetica, Arial, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei UI", "Microsoft YaHei", "Source Han Sans CN", sans-serif, "Apple Color Emoji", "Segoe UI Emoji"; margin-top: 14px; margin-bottom: 0px; font-size: 15px; line-height: 1.75; color: rgb(5, 7, 59); text-wrap: wrap;">以下是一个示例，展示多个中间件之间共享请求对象和响应对象：</p><pre style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; font-family: SFMono-Regular, Consolas, "Liberation Mono", Menlo, Courier, monospace; margin-top: 14px; margin-bottom: 0px; font-size: 15px; overflow: auto; border-radius: 6px; color: rgb(5, 7, 59);"><code class="language-javascript" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; font-family: SFMono-Regular, Consolas, "Liberation Mono", Menlo, Courier, monospace; margin: 0px; font-size: 1em; tab-size: 4;"><table class="hljs hljs-ln"><tbody style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;" class="firstRow"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><span class="hljs-keyword" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(121, 40, 161); line-height: 24px;">const</span> express = <span class="hljs-built_in" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(170, 93, 0); line-height: 24px;">require</span>(<span class="hljs-string" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: green; line-height: 24px;">'express'</span>);</td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><span class="hljs-keyword" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(121, 40, 161); line-height: 24px;">const</span> app = <span class="hljs-title function_" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(0, 127, 170); line-height: 24px;">express</span>();</td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><br/></td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><span class="hljs-comment" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(105, 105, 105); line-height: 24px;">// 定义第一个中间件 </span></td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;">app.<span class="hljs-title function_" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(0, 127, 170); line-height: 24px;">use</span>(<span class="hljs-function" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;">(<span class="hljs-params" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(170, 93, 0); line-height: 24px;">req, res, next</span>) =></span> {</td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><span class="hljs-variable language_" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(217, 30, 24); line-height: 24px;">console</span>.<span class="hljs-title function_" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(0, 127, 170); line-height: 24px;">log</span>(<span class="hljs-string" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: green; line-height: 24px;">'第一个中间件处理程序被调用'</span>);</td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><br/></td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><span class="hljs-comment" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(105, 105, 105); line-height: 24px;">// 在请求对象中添加一个属性 </span></td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;">req.<span class="hljs-property" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;">foo</span> = <span class="hljs-string" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: green; line-height: 24px;">'Hello from req.foo!'</span>;</td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><br/></td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><span class="hljs-comment" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(105, 105, 105); line-height: 24px;">// 在响应对象中添加一个属性 </span></td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;">res.<span class="hljs-property" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;">bar</span> = <span class="hljs-string" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: green; line-height: 24px;">'Hello from res.bar!'</span>;</td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><br/></td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><span class="hljs-title function_" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(0, 127, 170); line-height: 24px;">next</span>(); <span class="hljs-comment" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(105, 105, 105); line-height: 24px;">// 调用 next 函数以进行下一个中间件或路由处理程序 </span></td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;">});</td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><br/></td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><span class="hljs-comment" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(105, 105, 105); line-height: 24px;">// 定义第二个中间件 </span></td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;">app.<span class="hljs-title function_" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(0, 127, 170); line-height: 24px;">use</span>(<span class="hljs-function" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;">(<span class="hljs-params" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(170, 93, 0); line-height: 24px;">req, res, next</span>) =></span> {</td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><span class="hljs-variable language_" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(217, 30, 24); line-height: 24px;">console</span>.<span class="hljs-title function_" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(0, 127, 170); line-height: 24px;">log</span>(<span class="hljs-string" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: green; line-height: 24px;">'第二个中间件处理程序被调用'</span>);</td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><br/></td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><span class="hljs-comment" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(105, 105, 105); line-height: 24px;">// 访问请求对象中添加的属性 </span></td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><span class="hljs-variable language_" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(217, 30, 24); line-height: 24px;">console</span>.<span class="hljs-title function_" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(0, 127, 170); line-height: 24px;">log</span>(<span class="hljs-string" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: green; line-height: 24px;">`req.foo: <span class="hljs-subst" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;">${req.foo}</span>`</span>);</td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><br/></td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><span class="hljs-comment" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(105, 105, 105); line-height: 24px;">// 访问响应对象中添加的属性 </span></td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><span class="hljs-variable language_" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(217, 30, 24); line-height: 24px;">console</span>.<span class="hljs-title function_" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(0, 127, 170); line-height: 24px;">log</span>(<span class="hljs-string" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: green; line-height: 24px;">`res.bar: <span class="hljs-subst" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;">${res.bar}</span>`</span>);</td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><br/></td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><span class="hljs-title function_" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(0, 127, 170); line-height: 24px;">next</span>(); <span class="hljs-comment" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(105, 105, 105); line-height: 24px;">// 调用 next 函数以进行下一个中间件或路由处理程序 </span></td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;">});</td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><br/></td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><span class="hljs-comment" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(105, 105, 105); line-height: 24px;">// 定义一个路由处理程序 </span></td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;">app.<span class="hljs-title function_" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(0, 127, 170); line-height: 24px;">get</span>(<span class="hljs-string" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: green; line-height: 24px;">'/user'</span>, <span class="hljs-function" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;">(<span class="hljs-params" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(170, 93, 0); line-height: 24px;">req, res</span>) =></span> {</td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><span class="hljs-variable language_" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(217, 30, 24); line-height: 24px;">console</span>.<span class="hljs-title function_" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(0, 127, 170); line-height: 24px;">log</span>(<span class="hljs-string" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: green; line-height: 24px;">'路由处理程序被调用'</span>);</td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><br/></td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><span class="hljs-comment" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(105, 105, 105); line-height: 24px;">// 在路由处理程序中访问请求对象中添加的属性 </span></td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><span class="hljs-variable language_" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(217, 30, 24); line-height: 24px;">console</span>.<span class="hljs-title function_" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(0, 127, 170); line-height: 24px;">log</span>(<span class="hljs-string" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: green; line-height: 24px;">`req.foo: <span class="hljs-subst" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;">${req.foo}</span>`</span>);</td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><br/></td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><span class="hljs-comment" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(105, 105, 105); line-height: 24px;">// 在路由处理程序中访问响应对象中添加的属性 </span></td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><span class="hljs-variable language_" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(217, 30, 24); line-height: 24px;">console</span>.<span class="hljs-title function_" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(0, 127, 170); line-height: 24px;">log</span>(<span class="hljs-string" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: green; line-height: 24px;">`res.bar: <span class="hljs-subst" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;">${res.bar}</span>`</span>);</td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><br/></td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;">res.<span class="hljs-title function_" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(0, 127, 170); line-height: 24px;">send</span>(<span class="hljs-string" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: green; line-height: 24px;">'User page.'</span>);</td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;">});</td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><br/></td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;">app.<span class="hljs-title function_" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(0, 127, 170); line-height: 24px;">listen</span>(<span class="hljs-number" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(170, 93, 0); line-height: 24px;">80</span>, <span class="hljs-function" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;">() =></span> {</td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><span class="hljs-variable language_" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(217, 30, 24); line-height: 24px;">console</span>.<span class="hljs-title function_" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(0, 127, 170); line-height: 24px;">log</span>(<span class="hljs-string" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: green; line-height: 24px;">'Server is running on port 80'</span>);</td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;">});</td></tr></tbody></table></code></pre><p class="" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Ubuntu, "Helvetica Neue", Helvetica, Arial, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei UI", "Microsoft YaHei", "Source Han Sans CN", sans-serif, "Apple Color Emoji", "Segoe UI Emoji"; margin-top: 14px; margin-bottom: 0px; font-size: 15px; line-height: 1.75; color: rgb(5, 7, 59); text-wrap: wrap;">在这个示例中，我们定义了两个中间件函数和一个路由处理程序。在第一个中间件函数中，我们向请求对象添加了一个属性 <code class=" inline" style="box-sizing: border-box; padding: 1px 4px; -webkit-font-smoothing: antialiased; list-style: none; font-family: SFMono-Regular, Consolas, "Liberation Mono", Menlo, Courier, monospace; margin: 0px 2px; font-size: 12.75px; tab-size: 4; background-color: rgba(27, 31, 35, 0.05); border-radius: 3px;">req.foo</code>，并向响应对象添加了一个属性 <code class=" inline" style="box-sizing: border-box; padding: 1px 4px; -webkit-font-smoothing: antialiased; list-style: none; font-family: SFMono-Regular, Consolas, "Liberation Mono", Menlo, Courier, monospace; margin: 0px 2px; font-size: 12.75px; tab-size: 4; background-color: rgba(27, 31, 35, 0.05); border-radius: 3px;">res.bar</code>。然后，在第二个中间件函数中，我们访问了这些属性，并在控制台中输出它们的值。最后，在路由处理程序中，我们再次访问了这些属性并输出它们的值。当有多个中间件函数被注册到同一个路由时，它们可以共享请求对象和响应对象。</p><p><br/></p>
<p class="" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Ubuntu, "Helvetica Neue", Helvetica, Arial, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei UI", "Microsoft YaHei", "Source Han Sans CN", sans-serif, "Apple Color Emoji", "Segoe UI Emoji"; margin-top: 0px; margin-bottom: 0px; font-size: 15px; line-height: 1.75; color: rgb(5, 7, 59); text-wrap: wrap;">在 Node.js 中，全局中间件是一种特殊的中间件，它在所有路由处理程序之前被调用。全局中间件可以用于执行各种任务，例如验证用户身份、检查用户会话状态、解析请求数据等。</p><p class="" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Ubuntu, "Helvetica Neue", Helvetica, Arial, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei UI", "Microsoft YaHei", "Source Han Sans CN", sans-serif, "Apple Color Emoji", "Segoe UI Emoji"; margin-top: 14px; margin-bottom: 0px; font-size: 15px; line-height: 1.75; color: rgb(5, 7, 59); text-wrap: wrap;">要定义全局中间件，可以使用 <code class=" inline" style="box-sizing: border-box; padding: 1px 4px; -webkit-font-smoothing: antialiased; list-style: none; font-family: SFMono-Regular, Consolas, "Liberation Mono", Menlo, Courier, monospace; margin: 0px 2px; font-size: 12.75px; tab-size: 4; background-color: rgba(27, 31, 35, 0.05); border-radius: 3px;">app.use()</code> 函数。这个函数接受一个中间件函数作为参数，并将其注册为全局中间件。全局中间件会应用于所有路由和传入的请求对象（req）和响应对象（res）。</p><p class="" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Ubuntu, "Helvetica Neue", Helvetica, Arial, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei UI", "Microsoft YaHei", "Source Han Sans CN", sans-serif, "Apple Color Emoji", "Segoe UI Emoji"; margin-top: 14px; margin-bottom: 0px; font-size: 15px; line-height: 1.75; color: rgb(5, 7, 59); text-wrap: wrap;">以下是一个示例，展示如何定义一个全局中间件：</p><pre style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; font-family: SFMono-Regular, Consolas, "Liberation Mono", Menlo, Courier, monospace; margin-top: 14px; margin-bottom: 0px; font-size: 15px; overflow: auto; border-radius: 6px; color: rgb(5, 7, 59);"><code class="language-javascript" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; font-family: SFMono-Regular, Consolas, "Liberation Mono", Menlo, Courier, monospace; margin: 0px; font-size: 1em; tab-size: 4;"><table class="hljs hljs-ln"><tbody style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;" class="firstRow"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><span class="hljs-keyword" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(121, 40, 161); line-height: 24px;">const</span> express = <span class="hljs-built_in" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(170, 93, 0); line-height: 24px;">require</span>(<span class="hljs-string" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: green; line-height: 24px;">'express'</span>);</td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><span class="hljs-keyword" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(121, 40, 161); line-height: 24px;">const</span> app = <span class="hljs-title function_" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(0, 127, 170); line-height: 24px;">express</span>();</td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><br/></td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><span class="hljs-comment" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(105, 105, 105); line-height: 24px;">// 定义全局中间件 </span></td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;">app.<span class="hljs-title function_" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(0, 127, 170); line-height: 24px;">use</span>(<span class="hljs-function" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;">(<span class="hljs-params" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(170, 93, 0); line-height: 24px;">req, res, next</span>) =></span> {</td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><span class="hljs-variable language_" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(217, 30, 24); line-height: 24px;">console</span>.<span class="hljs-title function_" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(0, 127, 170); line-height: 24px;">log</span>(<span class="hljs-string" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: green; line-height: 24px;">'全局中间件处理程序被调用'</span>);</td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><br/></td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><span class="hljs-comment" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(105, 105, 105); line-height: 24px;">// 在这里执行你的代码逻辑 </span></td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><br/></td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><span class="hljs-title function_" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(0, 127, 170); line-height: 24px;">next</span>(); <span class="hljs-comment" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(105, 105, 105); line-height: 24px;">// 调用 next 函数以进行下一个中间件或路由处理程序 </span></td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;">});</td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><br/></td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><span class="hljs-comment" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(105, 105, 105); line-height: 24px;">// 定义一个路由处理程序 </span></td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;">app.<span class="hljs-title function_" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(0, 127, 170); line-height: 24px;">get</span>(<span class="hljs-string" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: green; line-height: 24px;">'/user'</span>, <span class="hljs-function" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;">(<span class="hljs-params" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(170, 93, 0); line-height: 24px;">req, res</span>) =></span> {</td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;">res.<span class="hljs-title function_" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(0, 127, 170); line-height: 24px;">send</span>(<span class="hljs-string" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: green; line-height: 24px;">'User page.'</span>);</td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;">});</td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><br/></td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;">app.<span class="hljs-title function_" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(0, 127, 170); line-height: 24px;">listen</span>(<span class="hljs-number" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(170, 93, 0); line-height: 24px;">80</span>, <span class="hljs-function" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;">() =></span> {</td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><span class="hljs-variable language_" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(217, 30, 24); line-height: 24px;">console</span>.<span class="hljs-title function_" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(0, 127, 170); line-height: 24px;">log</span>(<span class="hljs-string" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: green; line-height: 24px;">'Server is running on port 80'</span>);</td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;">});</td></tr></tbody></table></code></pre><p class="" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Ubuntu, "Helvetica Neue", Helvetica, Arial, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei UI", "Microsoft YaHei", "Source Han Sans CN", sans-serif, "Apple Color Emoji", "Segoe UI Emoji"; margin-top: 14px; margin-bottom: 0px; font-size: 15px; line-height: 1.75; color: rgb(5, 7, 59); text-wrap: wrap;">在这个示例中，我们使用 <code class=" inline" style="box-sizing: border-box; padding: 1px 4px; -webkit-font-smoothing: antialiased; list-style: none; font-family: SFMono-Regular, Consolas, "Liberation Mono", Menlo, Courier, monospace; margin: 0px 2px; font-size: 12.75px; tab-size: 4; background-color: rgba(27, 31, 35, 0.05); border-radius: 3px;">app.use()</code> 函数定义了一个全局中间件。这个中间件会在每个传入的 HTTP 请求时被调用，并在路由处理程序之前执行。在全局中间件中，我们可以执行任何我们需要的代码逻辑，例如验证用户身份、检查请求头、解析请求数据等。通过调用 <code class=" inline" style="box-sizing: border-box; padding: 1px 4px; -webkit-font-smoothing: antialiased; list-style: none; font-family: SFMono-Regular, Consolas, "Liberation Mono", Menlo, Courier, monospace; margin: 0px 2px; font-size: 12.75px; tab-size: 4; background-color: rgba(27, 31, 35, 0.05); border-radius: 3px;">next()</code> 函数，我们可以将控制权传递给下一个中间件或路由处理程序。</p><p><br/></p>