特快路线 404

Question

我的 node.js express 路由有问题。我真的很陌生，我看不到我的错误。请求 localhost:2700/api/subs 时总是出现 404 错误，但我认为我的路线是正确的，不是吗？有人能看出错误吗？

错误消息的开头：

Error: Not Found
at ****/app.js:45:13
at Layer.handle [as handle_request] (****/node_modules/express/lib/router/layer.js:95:5)

这里是 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');

const mongoose = require('mongoose');

// establish connection to the Database
mongoose.connect('mongodb://localhost/test', {
  useMongoClient: true
});

mongoose.connection.once('open', function() {
  console.log('Connection to Database has been established..');
}).on('error', function(error){
  console.log(error);
});


var index = require('./routes/index');
var users = require('./routes/users');
Subscriber = require('./routes/subscriber.js');

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('/', index);
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 handler
app.use(function(err, req, res, next) {
  // set locals, only providing error in development
  res.locals.message = err.message;
  res.locals.error = req.app.get('env') === 'development' ? err : {};

  // render the error page
  res.status(err.status || 500);
  res.render('error');
});

app.get('/api/subs', function(req, res){
    Subscriber.getSubscribers(function(err, subscribers){
        if(err){
            throw err;
        }
        res.json(subscribers);
    });
});

// ... here is a function which creates the database objects and saves         
//       them. took it out for better overview....

app.listen(2700, function(){
  console.log("Listening on Port 2700")
});

module.exports = app;

和 subscriber.js 位于子目录 ./routes:

const mongoose = require('mongoose');

var subscriberSchema = mongoose.Schema({
    //seqnr shall go here. dunno how to declare integer x)
    nr: Number,
    name: String,
    email: String,
    uLink: String,
    anwalt: String
});

var Subscriber = module.exports = mongoose.model('Subscriber', subscriberSchema);

//get Subscriber
module.exports.getSubscribers = function(callback, limit){
    Subscriber.find(callback).limit(limit);
};

index.js

var express = require('express');
var router = express.Router();

/* GET home page. */ 
router.get('/', function(req, res, next) {
  res.render('index', { title: 'Express' });
});

module.exports = router;

Answer 1

你需要把你的 404 app.use 放在所有其他用途之后，否则它会忽略它后面的api/subs。

此外，这个位永远不会运行，因为它也出现在api.use 之后，总是会抛出错误：

// error handler
app.use(function(err, req, res, next) {
  // set locals, only providing error in development
  res.locals.message = err.message;
  res.locals.error = req.app.get('env') === 'development' ? err : {};

  // render the error page
  res.status(err.status || 500);
  res.render('error');
});

另外，您真的不应该为 404 引发错误。它应该告诉最终用户该页面不存在，但它不应该使您的脚本崩溃。

我也同意另一个答案，即您应该将这些代码块移动到单独的路由器文件中，但这更多的是为了良好的实践和结构化而不是这个特定的错误。

Answer 2

尝试将它放在一个单独的文件中，并将它包含在您使用其他路由的位置，在 404 处理程序之前

app.use('/', index);
app.use('/users', users);

所以...创建一个subs.js 路由

var express = require('express');
var router = express.Router();
Subscriber = require('./routes/subscriber.js');

router.get('/', function(req, res){
    Subscriber.getSubscribers(function(err, subscribers){
        if(err){
            throw err;
        }
        res.json(subscribers);
    });
});

module.exports = router;

然后将其包含在您的app.js

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