restful API rest设计风格

理清restful API 基本含义
小结：

符合rest设计规范的应用就是使用了restful API

Node搭建 rest风格服务器代码：

var express = require('express');
var app = express();
var fs = require("fs");
const path = require("path")

app.get('/listUsers', function (req, res) {
   fs.readFile( __dirname + "/" + "users.json", 'utf8', function (err, data) {
       res.end( data );
   });
})

var user4 = {
  "name" : "add",
  "password" : "123",
  "profession" : "teacher",
  'id' : 4
}
app.get('/addUser', function(req,res){
  fs.readFile(path.join(__dirname,"/users.json"), "utf-8",function(err,data){
    data = JSON.parse(data)
    data.user4 = user4
    data = JSON.stringify(data)
    res.end(data)
    fs.writeFile(path.join(__dirname,"/users.json"),data,function(){})
  })
})

app.get('/:id' , function(req,res){
  const id = req.params.id
  fs.readFile(path.join(__dirname,"/users.json"), "utf-8",function(err,data){
    // 网络接收json文件，转换成js数据
    data = JSON.parse(data)
    data = data['user'+id]
    // 服务器发送出去只能是json文件
    data = JSON.stringify(data)
    res.end(data)
  })
})
//   http://localhost:8081/deleteUser/2
app.get('/deleteUser/:id' , function(req,res){
  const id = req.params.id
  fs.readFile(path.join(__dirname,"/users.json"), "utf-8",function(err,data){
    data = JSON.parse(data)
    // 俏皮，非要这么删除
    delete data["user" + id];
    data = JSON.stringify(data)
    fs.writeFile('/users.json',data,function(){})
    res.end(data)
  })
})

var server = app.listen(8081, function () {
  var host = server.address().address
  var port = server.address().port
  console.log("应用实例，访问地址为 http://%s:%s", host, port)
})

users.json

{"user1":{"name":"mahesh","password":"password1","profession":"teacher","id":1},"user2":{"name":"suresh","password":"password2","profession":"librarian","id":2},"user3":{"name":"ramesh","password":"password3","profession":"clerk","id":3},"user4":{"name":"add","password":"123","profession":"teacher","id":4}}