Express4 Route笔记

可以参考Express官网关于路由一节：http://expressjs.com/guide/routing.html

1:通过使用GET、POST方式定义主页路由，app.js:

var express = require('express');
var app = express();

app.get('/', function(req,res){
    res.send('欢迎来到Express首页');
});
app.post('/', function(req,res){
    res.send('Welcome to Express Index.');
});

2：路由路径以及参数定义

var express = require('express');
var app = express();

app.get('/users', function(req,res){
    res.send('获取用户列表');
});
app.get('/users/:id', function(req,res){
    res.send('user id:'+req.params.id);
});

浏览器中输入：http://127.0.0.1:3000/users/，http://127.0.0.1:3000/users/111

3：正则路由，值匹配方式与正则表达式一致，例如：

var express = require('express');
var app = express();

app.get('/ho?l', function(req,res){
    res.send('hl,hol');
});
app.get('/ho+l', function(req,res){
    res.send('hol,hool,hooool,and so on');
});
app.get('/ho*l', function(req,res){
    res.send('hol,holl,hoal,ho1000l,and so on');
});
app.get('/ho(ab)?l', function(req,res){
    res.send('hol,habl');
});

4：Route Handler:next()

var express = require('express');
var app = express();

app.get('/a/b', function(req,res,next){
    console.log('response will be send by the next function...');
    next();
},function(req,res){
    res.send('/a/b');
});

注意在next()所在的路由中，不能有输出，要在最后的处理函数中输出，否则后台会输出以下错误内容：

Error: Can't set headers after they are sent.
    at ServerResponse.OutgoingMessage.setHeader (http.js:689:11)
    at ServerResponse.header (/home/y/my_note/nodejs/myapp/node_modules/express/lib/response.js:662:10)
    at ServerResponse.send (/home/y/my_note/nodejs/myapp/node_modules/express/lib/response.js:146:12)
    at fn (/home/y/my_note/nodejs/myapp/node_modules/express/lib/response.js:896:10)
    at View.exports.renderFile [as engine] (/home/y/my_note/nodejs/myapp/node_modules/jade/lib/jade.js:325:12)
    at View.render (/home/y/my_note/nodejs/myapp/node_modules/express/lib/view.js:76:8)
    at Function.app.render (/home/y/my_note/nodejs/myapp/node_modules/express/lib/application.js:527:10)
    at ServerResponse.res.render (/home/y/my_note/nodejs/myapp/node_modules/express/lib/response.js:900:7)
    at module.exports (/home/y/my_note/nodejs/myapp/app.js:90:9)
    at Layer.handle_error (/home/y/my_note/nodejs/myapp/node_modules/express/lib/router/layer.js:58:5)

5：Response Methods

Method	Description
res.download()	Prompt a file to be downloaded.
res.end()	End the response process.
res.json()	Send a JSON response.
res.jsonp()	Send a JSON response with JSONP support.
res.redirect()	Redirect a request.
res.render()	Render a view template.
res.send()	Send a response of various types.
res.sendFile	Send a file as an octet stream.
res.sendStatus()	Set the response status code and send its string representation as the response body.

6：app.route()

app.route('/book')
    .get(function(req,res){
        res.send('get a book');
    })
    .post(function(req,res){
        res.send('add a book');
    })
    .put(function(req,res){
        res.send('update the book');
    });

7：Express.Router

app.js

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

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

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

index.js

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

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

module.exports = router;