express-test

app.js

const express = require("express");
// 本次 http 请求实例
const app = express();
app.use((req, res, next) => {
    console.log("请求开始...", req.method, req.url);
    next();
});
app.use((req, res, next) => {
    // 假设在处理 cookie
    req.cookie = {
        userId: "abc123",
    };
    next();
});
app.use((req, res, next) => {
    // 假设处理 post data
    // 异步
    setTimeout(() => {
        req.body = {
            a: 100,
            b: 200,
        };
        next();
    });
});
app.use("/api", (req, res, next) => {
    console.log("处理 /api 路由");
    next();
});
app.get("/api", (req, res, next) => {
    console.log("get /api 路由");
    next();
});
app.post("/api", (req, res, next) => {
    console.log("post /api 路由");
    next();
});
// 模拟登陆验证
function loginCheck(req, res, next) {
    // setTimeout(() => {
    //     console.log("模拟登陆成功");
    //     next();
    // });
    setTimeout(() => {
        console.log("登陆失败");
        res.json({
            error: -1,
            msg: "登陆失败",
        });
    });
}
app.get("/api/get-cookie", loginCheck, (req, res, next) => {
    console.log("get /api/get-cookie");
    res.json({
        error: 0,
        data: req.cookie,
    });
});
app.post("/api/get-post-data", (req, res, next) => {
    console.log("post /api/get-post-data");
    res.json({
        error: 0,
        data: req.body,
    });
});
app.use((req, res, next) => {
    console.log("处理 404");
    res.json({
        error: -1,
        msg: "404 not fount",
    });
});
app.listen(3000, () => {
    console.log("server is running no port 3000");
});

package.json

{
  "name": "express-test",
  "version": "1.0.0",
  "description": "",
  "main": "index.js",
  "scripts": {
    "test": "echo \"Error: no test specified\" && exit 1"
  },
  "keywords": [],
  "author": "",
  "license": "ISC",
  "dependencies": {
    "express": "^4.17.1"
  }
}