express是基于 Node.js 平台，快速、开放、极简的 web 开发框架。
开始
创建一个文件夹
$ mkdir express-test
进入express-test目录并创建包管理文件json
$ cd express-test
$ npm init
安装依赖包
$ npm install express body-parser ejs –save
创建一个app.js 入口文件
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
var express = require('express');
var bodyParser = require('body-parser');
var app = express();
//json类型的body 如果用户通过post发送的数据，则采用json解析
app.use(bodyParser.json());
//query string类型body 通过get请求url附带数据发送过来的解析方式
app.use(bodyParser.urlencoded({
extended: false
}));
//静态文件目录 请求一个文件时，优先到这个目录里找，找到返回
app.use(express.static(__dirname + '/public')); //把这个目录下的所有文件暴露给http接口
//路由与业务逻辑
app.set('view engine', 'ejs');//设置魔板引擎
app.set('views', __dirname + '/views');//设置魔板路径
app.get('/', function (req, res) {
res.render('index.ejs', {name: 'wen'});
});
app.use('/user', require('./routes/users.js')); //可以通过localhost:8000/user/list/ 访问
app.listen(8000);
启动项目
$ node app.js
在浏览器输入http://localhost:8000 测试效果 以及可以通过 http://localhost:8000/user/list 测试效果 对应源码看看为什么这样输出
test1.js 和test2.js是 挂载路径 app.mountpath 的例子
test1.js
1
2
3
4
5
6
7
8
9
10
//app.mountpath demo
var express = require('express');
var app = express(); // the main app
var admin = express(); // the sub app
admin.get('/', function (req, res) {
console.log(admin.mountpath); // /admin
res.send('Admin Homepage');
});
app.use('/admin', admin); // mount the sub app
app.listen(3000);
on get http://localhost:3000/admin the following is printed:
/admin
test2.js
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
var express = require('express');
var admin = express();
var app = express();
admin.get('/', function (req, res) {
console.log(admin.mountpath); // [ '/adm*n', '/manager' ]
res.send('Admin Homepage');
});
var secret = express();
secret.get('/', function (req, res) {
console.log(secret.mountpath); // /secr*t
res.send('Admin Secret');
});
admin.use('/secr*t', secret); // load the 'secret' router on '/secr*t', on the 'admin' sub app
app.use(['/adm*n', '/manager'], admin); // load the 'admin' router on '/adm*n' and '/manager', on the parent app
app.listen(3000);
on get http://localhost:3000/admin or http://localhost:3000/manager the following is printed:
[ ‘/adm*n’, ‘/manager’ ]
on get http://localhost:3000/admin/secret or http://localhost:3000/manage/secret the following is printed:
/secr*t
test3.js 是Events 事件监听的例子
1
2
3
4
5
6
7
8
9
10
11
12
var express = require('express');
var admin = express();
var app = express();
admin.on('mount', function (parent) {//监听mount事件
console.log('Admin Mounted');
console.log(parent); // refers to the parent app
});
admin.get('/', function (req, res) {
res.send('Admin Homepage');
});
app.use('/admin', admin);
app.listen(3000);
运行服务时就立马输出：Admin Mounted 和 输出指向父app的对象
on GET http://localhost:3000/admin the following is printed:
页面输出：Admin Homepage
test4.js 是使用回调函数数组处理路由例子
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
//使用回调函数数组处理路由
var express = require('express');
var app = express();
var cb0 = function (req, res, next) {
console.log('CB0');
next();
};
var cb1 = function (req, res, next) {
console.log('CB1');
next();
};
var cb2 = function (req, res) {
res.send('Hello from C!');
};
app.get('/', [cb0, cb1, cb2]);
app.listen(3000);
on GET http://localhost:3000 the following is printed:
CB0
CB1
Hello from C!
test5.js 是路由例子
1
2
3
4
5
var express = require('express');
var app = express();
var birds = require('./routes/birds');
app.use('/birds', birds);
app.listen(3000);
./routes/birds.js
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
var express = require('express');
var router = express.Router();
// 该路由使用的中间件
router.use(function timeLog(req, res, next) {
console.log('Time: ', Date.now());
next();
});
// 定义网站主页的路由
router.get('/', function(req, res) {
res.send('Birds home page');
});
// 定义 about 页面的路由
router.get('/about', function(req, res) {
res.send('About birds');
});
module.exports = router;
on GET http://localhost:3000/birds the following is printed:
Time: 1451011422551
页面显示：Birds home page
on GET http://localhost:3000/birds/about the following is printed:
Time: 1451011578836
页面显示：About birds
test6.js 是param参数方法的使用例子
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
var express = require('express');
var app = express();
app.param(['id', 'page'], function (req, res, next, value) {
console.log('CALLED ONLY ONCE with', value);
next();
});
app.get('/user/:id/:page', function (req, res, next) {
console.log('although this matches');
res.send(req.params);
next();
});
app.get('/user/:id/:page', function (req, res) {
console.log('and this matches too');
res.end();
});
app.listen(3000);
On GET /user/42/3, the following is printed:
CALLED ONLY ONCE with 42
CALLED ONLY ONCE with 3
although this matches
and this matches too
test7.js 是jsonp的使用例子
1
2
3
4
5
6
7
var express = require('express');
var app = express();
app.use(express.static('public'));
app.get('/test7', function(req ,res) {
res.jsonp({user: 'wen'});
});
app.listen(3000);
./public/test7.html
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>test7</title>
<script src="http://code.jquery.com/jquery-latest.js"></script>
</head>
<body>
<div><button id="btn">获取jsonp数据</button></label></div>
<div>输出：<span id="output"></span></div>
<script>
function foo(obj) {
console.log('执行了foo函数：输出 %s',obj.user);
}
$('#btn').click(function() {
$.getJSON('http://localhost:3000/test7?callback=?',function(data) {
console.log(data);
$('#output').html(data.user);
})
});
</script>
<script src="http://localhost:3000/test7?callback=foo"></script>
</body>
</html>
On GET http://localhost:3000/test7.html, the following is printed:
页面控制台此时输出了 “执行了foo函数：输出 wen” (说明页面加载时，执行了回调函数foo，并传入了服务器传回来的对象 {user: ‘wen’} 作为参数)
点击页面上的获取jsonp数据 按钮 即可看到页面显示 “输出：wen”
而控制面板则打印出对象： Object { user=“wen”}
以上可以对应启动项目
$ node test1.js
OR
$ node test2.js
类似以上对应启动项目测试用例
查看全部源码可以到我的github上下载：express-test
参考资料
Express 4.x API 中文手册