node.js - 为什么运行 Node.js 服务器时会出现此错误？

Question

我在运行 Node.js 服务器时收到此错误:

Error: Not Found
    at C:\wamp\www\scope-leads-node-master\MyApp\app.js:30:13
    at Layer.handle [as handle_request] (C:\wamp\www\scope-leads-node-master\MyApp\node_modules\express\lib\router\layer.js:95:5)
    at trim_prefix (C:\wamp\www\scope-leads-node-master\MyApp\node_modules\express\lib\router\index.js:312:13)
    at C:\wamp\www\scope-leads-node-master\MyApp\node_modules\express\lib\router\index.js:280:7
    at Function.process_params (C:\wamp\www\scope-leads-node-master\MyApp\node_modules\express\lib\router\index.js:330:12)
    at next (C:\wamp\www\scope-leads-node-master\MyApp\node_modules\express\lib\router\index.js:271:10)
    at C:\wamp\www\scope-leads-node-master\MyApp\node_modules\express\lib\router\index.js:618:15
    at next (C:\wamp\www\scope-leads-node-master\MyApp\node_modules\express\lib\router\index.js:256:14)
    at Function.handle (C:\wamp\www\scope-leads-node-master\MyApp\node_modules\express\lib\router\index.js:176:3)
    at router (C:\wamp\www\scope-leads-node-master\MyApp\node_modules\express\lib\router\index.js:46:12)

    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 app = express();    // view engine setup    app.set('views', path.join(__dirname, 'views'));    app.set('view engine', 'jade');    // 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: false }));    app.use(cookieParser());    app.use(express.static(path.join(__dirname, 'public')));    app.use('/', routes);    app.use('/users', users);    // catch 404 and forward to error handler    app.use(function(req, res, next) {      var err = new Error('Not Found');      err.status = 404;      next(err);    });    // error handlers    // 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;

Answer 1

这是您在编写的中间件中传递的错误(第 30 行):

app.use(function(req, res, next) {
  var err = new Error('Not Found');
  err.status = 404;
  next(err);
});

此代码只是在每个 HTTP 请求上传递一个错误，您应该将其注释掉。