Question

每当我尝试从索引提交时，我都会收到错误消息。我试图从用户名和密码输入中获取值。

这应该是处理帖子的代码：

app.post('/', function(req, res){
  var username=req.body.username;
  var password=req.body.password;
  res.render("the username and password you posted:" +password+username);
  });

我的app.js

var express = require('express');
var path = require('path');
var favicon = require('serve-favicon');
var logger = require('morgan');
var cookieParser = require('cookie-parser');
var bodyParser = require('body-parser');

var routes = require('./routes/index');
var users = require('./routes/users');
var patienten = require('./routes/patienten');
var form = require('./routes/form');

var app = express();

// view engine setup
app.set('views', path.join(__dirname, 'views'));
app.set('view engine', 'ejs');

// uncomment after placing your favicon in /public
//app.use(favicon(path.join(__dirname, 'public', 'favicon.ico')));
app.use(logger('dev'));
app.use(bodyParser.json());
app.use(bodyParser.urlencoded({ extended: true }));
app.use(cookieParser());
app.use(express.static(path.join(__dirname, 'public')));
app.use(bodyParser.json());

app.use('/', routes);
app.use('/users', users);
app.use('/patienten', patienten);
app.use('/form', form);

// catch 404 and forward to error handler
app.use(function(req, res, next) {
  var err = new Error('Not Found');
  err.status = 404;
  next(err);
});

app.get("/", function(req, res) {
  res.send("i am from /get");
});

app.get("/", function(req, res){
  res.sendfile("/");
});
app.post('/', function(req, res){
  var username=req.body.username;
  var password=req.body.password;
  res.render("the username and password you posted:" +password+username);
});

// development error handler
// will print stacktrace
if (app.get('env') === 'development') {
  app.use(function(err, req, res, next) {
    res.status(err.status || 500);
    res.render('error', {
      message: err.message,
      error: err
    });
  });
}
// production error handler
// no stacktraces leaked to user
app.use(function(err, req, res, next) {
  res.status(err.status || 500);
  res.render('error', {
    message: err.message,
    error: {}
  });
});


module.exports = app;

form.js

var express = require('express');
var router = express.Router();
var mysqlModel = require('mysql-model');
var request = require('request');
var ejs = require('querystring');

/* GET home page. */
router.get('/form', function(req, res) {
    res.render('form', {
        title: 'EPD - Login',
    });
});

module.exports = router;

form.ejs（提交页面）

<!DOCTYPE html>
<html>
  <head>
    <title><%= title %></title>
    <link rel='stylesheet' href='/stylesheets/style.css' />
  </head>
  <body>
    <form  action="/" method="GET">
<input type="text" name="username">
        <input type="password" name="password">
        <input type="submit" name="submit" value="gogo">
    </form>
  </body>
</html>

Answer 1

您不能使用res.render()将常规回复反馈给客户。请改用res.send()。这就是您收到错误的原因。 res.render()用于Express中的视图引擎，并将呈现的视图模板发送回客户端。在这种情况下，IE ejs是定义的视图引擎，这就是下面的代码正在做什么

// view engine setup
// Tells express to render from the views directory
app.set('views', path.join(__dirname, 'views')); 
app.set('view engine', 'ejs');

您的404处理程序应该是您的快速主文件中的第二个到最后一个路由，因为它是 所有与您定义的路由不匹配的路由 因为快递通过路线自上而下。除了在Express应用程序中的错误位置定义404处理程序外，您还应检查可能与路径发生的冲突。

您有以下路由器中间件

app.use('/', routes);

然后是以下GET路线

app.get("/", function(req, res) {
  res.send("i am from /get");
});

根据routes文件的内容，可能会发生冲突，app.get()永远不会被执行。

您应该按如下方式设置路线：

app.use('/', routes);
app.use('/users', users);
app.use('/patienten', patienten);
app.use('/form', form);

// If you have a GET inside your 'routes' file
// from above, then this may never get called if 
// it also contains a route for GET '/'
app.get("/", function(req, res) {
  console.log('I am from get');
  return res.render('index');
});


// My comment from above about your GET '/' would
// also apply to this POST route 
app.post('/', function(req, res){
  var username=req.body.username;
  var password=req.body.password;
  return res.status(200).send("the username and password you posted: " + password + ' ' + username);
});

// catch 404 and forward to error handler
app.use(function(req, res, next) {
  var err = new Error('Not Found');
  err.status = 404;
  return next(err);
});

// development error handler
// will print stacktrace
if (app.get('env') === 'development') {
  app.use(function(err, req, res, next) {
    res.status(err.status || 500);
    return res.render('error', {
      message: err.message,
      error: err
    });
  });
}
// production error handler
// no stacktraces leaked to user
app.use(function(err, req, res, next) {
  res.status(err.status || 500);
  return res.render('error', {
    message: err.message,
    error: {}
  });
});

您还需要将HTTP Method文件中指定的form.ejs从GET更改为POST

<form action="/" method="POST">

Answer 2

这个用于处理404的中间件应放在最后一条路线之后。 否则根据您的代码，您的所有匹配都将返回404 。

// catch 404 and forward to error handler
app.use(function(req, res, next) {
  var err = new Error('Not Found');
  err.status = 404;
  next(err);
});

此外，您的表单应发送POST请求而不是GET

<form  action="/" method="POST">

此外，res.render用于渲染视图。您可以根据需要使用res.send或res.json。

app.post('/', function(req, res){
  var username=req.body.username;
  var password=req.body.password;
  res.send("the username and password you posted:" +password+username);
});

postjs上的nodejs错误404（不是通过url）

2 个答案: