// 数据存储在users.json文件中const express = require("express");const fs = require("fs");const cors = require("cors");const bodyParser = require("body-parser");const app = express();app.use(cors({ origin: "*" })); // fix 跨域app.use(bodyParser.json()); // for parsing application/jsonapp.use(bodyParser.urlencoded({ extended: true })); // for parsing application/x-www-form-urlencoded// 新增app.post("/addUser", (req, res) => { fs.readFile("./users.json", "utf8", (err, data) => { if (err) { throw err; } data = data ? JSON.parse(data) : []; data.push(req.body); fs.writeFile("./users.json", JSON.stringify(data), err => { if (err) throw err; res.end(); }); });});// 删除app.delete("/delUser/:id", (req, res) => { const id = req.params.id; fs.readFile("./users.json", "utf8", (err, data) => { data = JSON.parse(data) || []; const saveData = data.filter(item => item.id != id); fs.writeFile("./users.json", JSON.stringify(saveData), err => { if (err) throw err; res.end(); }); });});// 修改app.put("/update/:id", (req, res) => { const id = req.params.id; const body = req.body; fs.readFile(__dirname + "/" + "users.json", "utf8", (err, data) => { const userList = (data && JSON.parse(data)) || []; const index = userList.findIndex(item => item.id == id); userList[index] = { ...userList[index], ...body }; fs.writeFile("./users.json", JSON.stringify(userList), err => { if (err) throw err; console.log("修改"); res.end(); }); });});// 列表查询app.get("/listUsers", function(req, res) { fs.readFile(__dirname + "/" + "users.json", "utf8", function(err, data) { console.log(data); res.end(data); });});app.listen(8081, function() { console.log("访问地址: http://localhost:8081");}); 
