express使用

1、安装express命令

cnpm install express --save

2、使用方法

var express = require('express');

var app = express();

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

var server = app.listen(8081)

3、内置的中间件 express.static

使用 express.static 中间件来设置静态文件路径。app.use(express.static('public'));

4、get请求:req.query获取发送的数据

//index.html文件
<!DOCTYPE html>
<html>
<body>
  <form action="http://localhost:8081/getmethod" method="GET">
    First Name: <input type="text" name="first_name">  <br>
    Last Name: <input type="text" name="last_name">
    <input type="submit" value="Submit">
  </form>
</body>
</html>

//请求文件server.js
var express = require('express');
var app = express();
app.use(express.static('public'));
app.get('/index.html',function(req,res){
    res.sendFile(__dirname + '/'+'index.html')
})
app.get('/getmethod',function(req,res){
    var data = req.query;
    console.log(req.query)
    res.send(req.query);
})
app.listen(8081)

执行：node server

浏览器访问：http://localhost:8081/index.html

5、post请求:req.body获取发送的数据

<!DOCTYPE html>
<html>
    <head>
        <meta charset="UTF-8">
        <title></title>
    </head>
    <body>
        <form action="http://localhost:8082/process_post" method="post">
            first name:<input type="text" name="first_name"/><br />
            last name: <input type="text" name="last_name" />
            <input type="submit" value="submit"/>
        </form>
    </body>
</html>

//请求文件server.js
var express = require('express');
var app = express();
app.listen('8082')
app.use(express.json())
app.use(express.urlencoded({extended:true}))
app.use('/post.html',function(req,res){
    res.sendFile(__dirname + '/'+'post.html')
})
app.use('/process_post',function(req,res){
    var data = req.body;
    console.log(data);
    res.send(data)
})

执行：node server

浏览器访问：http://localhost:8082/index.html

6、express.router()