POST请求与GET请求

get和post是HTTP协议中的两种发送请求的方法

HTTP是基于TCP/IP的关于数据如何在万维网中通信的协议

 一、get请求与querystring

get请求即客户端向server服务端请求数据，如：获取文章列表的分页码等

通过queryString来获取数据，如：liet.html?t=a&page=2

通过浏览器直接访问一个地址即发送get请求，如：地址栏输入url或者点击超链接访问页面

通过URL模块来获取get请求数据

const http = require('http');
const url = require('url');
const querystring = require('querystring');
http.createServer(function(req, res){

    res.writeHead(200, {'Content-Type': 'text/plain;charset=utf8'});
    //解析URL参数
    let params = url.parse(req.url, true).query;
    res.write('网站名' + params.name);
    res.write('\n');
    res.write('网站URL：' + params.url);
    res.end();

}).listen(3000);

二、post请求与postdata

post请求，即客户端向服务器传递数据，如微博发布文章等

通过post data传递数据

浏览器无法直接模拟，使用postman来模拟post请求发送数据

const server = http.createServer(function(req, res){
    let str = "", i=0;
    req.on('data', function(data){
        console.log(`第${i++}次请求接收数据`);
        str += data;
    });
    res.on('end', function(){
        let post = querystring.parse(str);
        console.log(str);
        res.end(str);
    })
});

server.listen(8080);

三、综合案例

    
    
    
    



    用户名：

    密码：

    
    

const http = require('http');
const querystring = require('querystring');
let users = {'admin': 12345, 'Tom': 123};

const server = http.createServer((req, res)=>{
    res.writeHead(200, {
        'Access-Control-Allow-Origin': '*',
        'Content-Type': 'application/json;charset=utf-8'
    });
    let postData = '';
    req.on('data', chunk => {
        postData += chunk;
    })
    req.on('end', ()=>{
        if(req.url != '/favicon.ico'){
            // console.log(postData)
            let obj = querystring.parse(postData);
            // console.log(obj.username);
            let username = obj.username;
            let password = obj.password;
            let act = obj.act;
            console.log(req.url)
            if(req.url == '/user1'){
                switch(act){
                    case 'reg':
                        if(users[username]){
                            res.write('{"flag": false, "msg": "此账号已存在！"}');
                        }else{
                            users[username] = password;
                            res.write('{"flag": true, "msg": "注册成功！"}');
                        }
                        break;
                    case 'login':
                        if(users[username] == null){
                            res.write('{"flag": false, "msg": "此账号不存在！"}');
                        }else if(users[username] !== password){
                            res.write('{"flag": false, "msg": "密码错误！"}');
                        }else {
                            res.write('{"flag": true, "msg": "登录成功！"}');
                        }
                        break;
                }
            }
        }
        res.end();
    })


});
server.listen(3000, ()=>{});

const http = require('http');
let users = {'admin': 12345, 'Tom': 123};

const server = http.createServer((req, res)=>{

    if(req.url != '/favicon.ico'){
        let obj = new URL(req.url, 'http://127.0.0.1/');
        let username = obj.searchParams.get('username');
        let password = obj.searchParams.get('password');
        let act = obj.searchParams.get('act');

        res.writeHead(200, {
            // 只针对某个地址实现跨域
            // 'Access-Control-Allow-Origin': 'http://127.0.0.1:5500',
            // 所有请求都允许跨域
            'Access-Control-Allow-Origin': '*',
            'Content-Type': 'application/json;charset=utf-8'
        });
        let url=req.url.split('?')[0];
        if(url == '/user'){
            switch(act){
                case 'reg':
                    if(users[username]){
                        res.write('{"flag": false, "msg": "此账号已存在！"}');
                    }else{
                        users[username] = password;
                        res.write('{"flag": true, "msg": "注册成功！"}');
                    }
                    break;
                case 'login':
                    if(users[username] == null){
                        res.write('{"flag": false, "msg": "此账号不存在！"}');
                    }else if(users[username] !== password){
                        res.write('{"flag": false, "msg": "密码错误！"}');
                    }else {
                        res.write('{"flag": true, "msg": "登录成功！"}');
                    }

                    break;
            }
        }
    }
    res.end();
});
server.listen(3000, ()=>{});