javascript - 错误 [ERR_HTTP_HEADERS_SENT] : Cannot set headers after they are sent to the client, 我无法发送表单

Question

每当我想在我的 View (ejs)中填写表单并发送到数据库时，我总是在终端中收到此错误。

    MongoDB Connected



    Error [ERR_HTTP_HEADERS_SENT]: Cannot set headers after they are sent to the client
        at ServerResponse.setHeader (_http_outgoing.js:485:11)
        at ServerResponse.header (/home/codabae/Documents/mailmonster/api/v1/node_modules/express/lib/response.js:767:10)
        at ServerResponse.send (/home/codabae/Documents/mailmonster/api/v1/node_modules/express/lib/response.js:170:12)
        at done (/home/codabae/Documents/mailmonster/api/v1/node_modules/express/lib/response.js:1004:10)
        at tryHandleCache (/home/codabae/Documents/mailmonster/api/v1/node_modules/ejs/lib/ejs.js:257:5)
        at View.exports.renderFile [as engine] (/home/codabae/Documents/mailmonster/api/v1/node_modules/ejs/lib/ejs.js:482:10)
        at View.render (/home/codabae/Documents/mailmonster/api/v1/node_modules/express/lib/view.js:135:8)
        at tryRender (/home/codabae/Documents/mailmonster/api/v1/node_modules/express/lib/application.js:640:10)
        at Function.render (/home/codabae/Documents/mailmonster/api/v1/node_modules/express/lib/application.js:592:3)
        at ServerResponse.render (/home/codabae/Documents/mailmonster/api/v1/node_modules/express/lib/response.js:1008:7)
        at /home/codabae/Documents/mailmonster/api/v1/node_modules/express-ejs-layouts/lib/express-layouts.js:113:20
        at tryHandleCache (/home/codabae/Documents/mailmonster/api/v1/node_modules/ejs/lib/ejs.js:257:5)
        at View.exports.renderFile [as engine] (/home/codabae/Documents/mailmonster/api/v1/node_modules/ejs/lib/ejs.js:482:10)
        at View.render (/home/codabae/Documents/mailmonster/api/v1/node_modules/express/lib/view.js:135:8)
        at tryRender (/home/codabae/Documents/mailmonster/api/v1/node_modules/express/lib/application.js:640:10)
        at Function.render (/home/codabae/Documents/mailmonster/api/v1/node_modules/express/lib/application.js:592:3)

这是我的代码

我的看法

    <h1 class="mt-4">Dashboard</h1>
    <div class="row mt-5">
        <div class="col-md-6 m-auto">
          <div class="card card-body">
            <h1 class="text-center mb-3">
              <i class="fas fa-user-plus"></i> Add Smtp
            </h1>
            <% include ./partials/messages %>
            <form action="/users/mail" method="POST">
              <div class="form-group">
                <label for="smtpUsername">smtpUsername</label>
                <input
                  type="name"
                  id="smtpUsername"
                  name="smtpUsername"
                  class="form-control"
                  placeholder="Enter smtpUsername"
                  value="<%= typeof smtpUsername != 'undefined' ? smtpUsername : '' %>"
                />
              </div>
              <div class="form-group">
                <label for="smtpPassword">smtpPassword</label>
                <input
                  type="name"
                  id="smtpPassword"
                  name="smtpPassword"  
                  class="form-control"
                  placeholder="Enter smtpPassword"
                  value="<%= typeof smtpPassword != 'undefined' ? smtpPassword : '' %>"
                />
              </div>
              <div class="form-group">
                <label for="smtpUrl">smtpUrl</label>
                <input
                  type="name"
                  id="smtpUrl"
                  name="smtpUrl"
                  class="form-control"
                  placeholder="Enter smtpUrl"
                  value="<%= typeof smtpUrl != 'undefined' ? smtpUrl : '' %>"
                />
              </div>
              <button type="submit" class="btn btn-primary btn-block">
                Add Smtp
              </button>
            </form>
          </div>
        </div>
      </div>



    <div class="row mt-5">
        <div class="col-md-6 m-auto">
          <div class="card card-body">
            <h1 class="text-center mb-3">
              <i class="fas fa-user-plus"></i> send mail
            </h1>
            <% include ./partials/messages %>
            <form action="/users/mail" method="POST">
              <div class="form-group">
                <label for="to">to</label>
                <input
                  type="name"
                  id="to"
                  name="to"
                  class="form-control"
                  placeholder="Enter to"
                  value="<%= typeof to != 'undefined' ? to : '' %>"
                />
              </div>
              <div class="form-group">
                <label for="bcc">bcc</label>
                <input
                  type="name"
                  id="bcc"
                  name="bcc"
                  class="form-control"
                  placeholder="Enter bcc"
                  value="<%= typeof bcc != 'undefined' ? bcc : '' %>"
                />
              </div>
              <div class="form-group">
                <label for="cc">cc</label>
                <input
                  type="name"
                  id="cc"
                  name="name"
                  class="form-control"
                  placeholder="Enter cc"
                  value="<%= typeof cc != 'undefined' ? cc : '' %>"
                />
              </div>
              <div class="form-group">
                <label for="subject">subject</label>
                <input
                  type="name"
                  id="subject"
                  name="subject"
                  class="form-control"
                  placeholder="Enter subject"
                  value="<%= typeof subject != 'undefined' ? subject : '' %>"
                />
              </div>
              <div class="form-group">
                <label for="message">message</label>
                <input
                  type="name"
                  id="message"
                  name="message"
                  class="form-control"
                  placeholder="Enter message"
                  value="<%= typeof message != 'undefined' ? message : '' %>"
                />
              </div>
              <button type="submit" class="btn btn-primary btn-block">
                Register
              </button>
            </form>
          </div>
        </div>
      </div>



    <a href="/users/logout" class="btn btn-secondary">Logout</a>

我的路线

    router.get('/mail', forwardAuthenticated, (req, res) =>
        res.render('mail', {
            user: req.user,
            mail: req.mail

        })
    );
    router.post('/mail', (req, res) => {
        const { to, cc, bcc, subject, message, attachment,smtpUrl, smtpUsername, smtpPassword  } = req.body;

        console.log(smtpUrl)
        console.log(smtpPassword)
        console.log(smtpUsername)



        let errors = [];

        if (!smtpUrl || !smtpUsername || !smtpPassword) {
            errors.push({ msg: 'Add an account' });
            res.render('mail', {
            smtpUrl,
            smtpPassword,
            smtpUsername
            });

        }else{
          console.log(smtpUrl)
          console.log(smtpPassword)
          console.log(smtpUsername)
          const newSmtp = new Smtp({
            smtpUrl,
            smtpPassword,
            smtpUsername
        });

        newSmtp
        .save()
        .then(mail => {
            req.flash(
                'success_msg',
                'Account Added'
            );

        })
        .catch(err => console.log(err));
        }
        if (!to || !subject || !message) {
            errors.push({ msg: 'Please enter all fields' });
        }


        if (errors.length > 0) {
            res.render('mail', {
                errors,
                to,
                cc,
                bcc,
                subject,
                message,
                attachment,
            });
        } else {
            const newMail = new Mail({
                to,
                cc,
                bcc,
                subject,
                message,
                attachment,
            });


            let transporter = nodemailer.createTransport({
                service: smtpUrl,
                auth: {
                    user: smtpUsername,
                    pass: smtpPassword
                }
            });

            let mailOptions = {
                from: smtpUsername,
                to: to,
                subject: subject,
                text: `${message}`
            };

            transporter.sendMail(mailOptions, function (error, info) {
                if (error) {
                    console.log(error);
                } else {

                    newMail
                        .save()
                        .then(mail => {
                            req.flash(
                                'success_msg',
                                'mail sent'
                            );

                        })
                        .catch(err => console.log(err));
                    console.log('Email sent: ' + info.response);
                }
            });





        }


    })

    // Login
    router.post('/login', (req, res, next) => {
      passport.authenticate('local', {
        successRedirect: '/users/mail',
        failureRedirect: '/users/login',
        failureFlash: true
      })(req, res, next);
    });

    // Logout
    router.get('/logout', (req, res) => {
      req.logout();
      req.flash('success_msg', 'You are logged out');
      res.redirect('/users/login');
    });

我的架构

    const mongoose = require('mongoose');

    const MailSchema = new mongoose.Schema({
        to: {
            type: String,

        },
        cc: {
            type: String,

        },
        bcc: {
            type: String,
        },
        subject: {
            type: String,

        },
        message: {  
            type: String,

        },
        attachment: {
            type: String,
        },
        date: {
            type: Date,
            default: Date.now
        },

    });

    const SmtpSchema = new mongoose.Schema({
        smtpUrl: {
            type: String,
            required: true

        },
        smtpUsername: {
            type: String,
            required: true

        },
        smtpPassword: {
            type: String,
            required: true

        },
        date: {
            type: Date,
            default: Date.now
        },

    });





    const Mail = mongoose.model('Mail', MailSchema);
    const Smtp = mongoose.model('Smtp', SmtpSchema);


    module.exports = Mail;
    module.exports = Smtp;

每当我想在我的 View (ejs)中填写表单并发送到数据库时，我总是在终端中收到此错误。

错误 [ERR_HTTP_HEADERS_SENT]:将 header 发送到客户端后无法设置 header ，我无法发送表单错误 [ERR_HTTP_HEADERS_SENT]:将 header 发送到客户端后无法设置 header ，我无法发送表单错误 [ERR_HTTP_HEADERS_SENT]:将 header 发送到客户端后无法设置 header ，我无法发送表单错误 [ERR_HTTP_HEADERS_SENT]:将 header 发送到客户端后无法设置 header ，我无法发送表单

Answer 1

当您在router.post('/mail'中添加smtp部分出错时，您会继续发送邮件，因此在某些情况下您应该两次向客户端发送响应，这是不可能的。您的根本问题是您在单个路由器路径和方法中执行两项不同的工作。我强烈建议将两者分开。我看到您有另一个问题，在单个页面中具有相同操作的 2 个表单(它是 POST 在路径 /mail 中)，通过分离该问题将得到解决。