Express路由

路由（Router）是指应用程序的端点（URI）如何响应客户端请求。Express，提供了路由功能用来封装请求。创建一个路由，express.router()。

通俗解释：

http://host[:port][path]，http：表示网络协议；host：表示主机；port：表示端口，可选字段，默认为80；path：指定请求资源的URI（统一资源标识符），URL没有给出path，一般会默认为："/"。路由，就是处理HTTP请求中的路径部分。

案例代码1：

工程结构

──项目
    │  app.js
    │  
    ├─controller
    │      api_v1.js
    │      api_v2.js

app.js

const express = require("express");
var app = express();

app.use('/api/v1', require('./controller/api_v1'));
app.use('/api/v2', require('./controller/api_v2'));

app.get('/', function (req, res) {
  res.send('Hello from root route.')
});

app.listen(3000);
console.log('Express started on port 3000');

controller/api_v1.js

const express = require("express");

var apiv1 = express.Router();

apiv1.get('/', function(req, res) {
  res.send('apiv1 /');
});

apiv1.get('/users', function(req, res) {
  res.send('apiv1 /users');
});

module.exports = apiv1;

controller/api_v2.js

const express = require("express");

var apiv2 = new express.Router();

apiv2.get('/', function (req, res) {
  res.send('apiv2 /');
});

apiv2.get('/users', function (req, res) {
  res.send('apiv2 /users');
});

module.exports = apiv2;

访问地址

http://127.0.0.1:3000/
http://127.0.0.1:3000/api/v1
http://127.0.0.1:3000/api/v1/users
http://127.0.0.1:3000/api/v2
http://127.0.0.1:3000/api/v2/users

案例代码2：

工程结构

──项目
    │  app.js
    │  
    ├─routes
    │     home.js
    │      admin.js
    │────admin
    │             user.js
    │             goods.js

app.js

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

//引入模块
var admin = require('./routes/admin.js');
var home = require('./routes/home.js');

app.use('/home', home);   // 前台(路由)  http://127.0.0.1:3000/home
app.use('/admin', admin);  // 后台(路由) 127.0.0.1:3000/admin
app.use('/', home);     // 默认加载前台(路由)

app.listen(3000, '127.0.0.1');

routes/home.js

const express = require("express");
var router = new express.Router();

// http://127.0.0.1:3000/home
router.get('/', function (req, res) {
  res.send('前台默认页面');
});

// http://127.0.0.1:3000/home/show
router.get('/show', function (req, res) {
  res.send('前台显示页面');
});

module.exports = router; 

routes/admin.js

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

var goods = require('./admin/goods.js');
var user = require('./admin/user.js');

//配置路由
router.use('/goods', goods);   // http://127.0.0.1:3000/admin/goods
router.use('/user', user);    // http://127.0.0.1:3000/admin/user
router.use('/', user);

//暴露router模块
module.exports = router; 

routes/admin/user.js

const express = require("express");
var router = express.Router();

// http://127.0.0.1:3000/admin/user
router.get('/', function (req, res) {
  res.send('用户>>>>>>>>>首页');
});

// http://127.0.0.1:3000/admin/user/add
router.get('/add', function (req, res) {
  res.send('用户>>>>>>>>>增加');
});

// http://127.0.0.1:3000/admin/user/edit
router.get('/edit', function (req, res) {
  res.send('用户>>>>>>>>>修改');
});

// http://127.0.0.1:3000/admin/user/delete
router.get('/delete', function (req, res) {
  res.send('用户>>>>>>>>>删除');
});

module.exports = router; 

routes/admin/goods.js

const express = require("express");
var router = express.Router();

// http://127.0.0.1:3000/admin/goods
router.get('/', function (req, res) {
  res.send('商品>>>>>>>>>首页');
});

// http://127.0.0.1:3000/admin/goods/add
router.get('/add', function (req, res) {
  res.send('商品>>>>>>>>>增加');
});

// http://127.0.0.1:3000/admin/goods/edit
router.get('/edit', function (req, res) {
  res.send('商品>>>>>>>>>修改');
});

// http://127.0.0.1:3000/admin/goods/delete
router.get('/delete', function (req, res) {
  res.send('商品>>>>>>>>>删除');
});

module.exports = router;