express 写接口

实例下载：百度云盘免密码

(): 指注释

一、准备工作

    1.安装express
        npm install express -g
        npm install express-generator -g

    2.初始化项目
        express APIServer(项目名称)
        cd APIServer && npm install

二、启动服务器
    npm start
    启动完成后终端将输出 node ./bin/www
    在浏览器中访问 http://localhost:3000/

三、基本使用
    定义一个路由的基本格式为：
    app.METHOD(PATH, HANDLER)

    想要实现一个获取用户信息接口该怎么写呢？(获取url参数 依赖于url模块)
    /routers/user.js
        function User() {
              this.name;
              this.city;
              this.age;
        }
        module.exports = User;

    /routers/users.js
        var User = require('./user');
        var URL = require('url');
        router.get('/getUserInfo', function(req, res, next) {
            var user = new User();
            var params = URL.parse(req.url, true).query;
            if(params.id == '1') {
                user.name = "ligh";
                user.age = "1";
                user.city = "北京市";
            }else{
                user.name = "SPTING";
                user.age = "1";
                user.city = "杭州市";
            }
            var response = {status:1,data:user};
            res.send(JSON.stringify(response));
        });

        调用方式（可在浏览器打开）
        http://localhost:3000/users/getUserInfo?id=1
        http://localhost:3000/users/getUserInfo?id=2

四、Post请求额外处理
    1.引用body-parser中间件
        var bodyParser = require('body-parser')
        app.use(bodyParser.json());
        app.use(bodyParser.urlencoded({ extended: false }));
    2.允许跨域
        app.use(function(req, res, next) {
            res.header("Access-Control-Allow-Origin", "*");
            res.header("Access-Control-Allow-Headers", "Origin, X-Requested-With, Content-Type, Accept");
            next();
        });

实例：修改/app.js 和 /routes/all.js两个文件
/app.js

var express = require('express');
var path = require('path');
var favicon = require('serve-favicon');
var logger = require('morgan');
var cookieParser = require('cookie-parser');
var bodyParser = require('body-parser');

var app = require('./routes/all');

/*
var index = require('./routes/index');
var users = require('./routes/users');
var app = express();
app.use('/', index);
app.use('/users', users);
var login = require('./routes/login');
app.use('/login', login);
*/

// view engine setup
app.set('views', path.join(__dirname, 'views'));
app.set('view engine', 'jade');

// uncomment after placing your favicon in /public
//app.use(favicon(path.join(__dirname, 'public', 'favicon.ico')));
app.use(logger('dev'));
app.use(bodyParser.json());
app.use(bodyParser.urlencoded({ extended: false }));
app.use(cookieParser());
app.use(express.static(path.join(__dirname, 'public')));
// catch 404 and forward to error handler
app.use(function(req, res, next) {
  var err = new Error('Not Found');
  err.status = 404;
  next(err);
});

// error handler
app.use(function(err, req, res, next) {
  // set locals, only providing error in development
  res.locals.message = err.message;
  res.locals.error = req.app.get('env') === 'development' ? err : {};

  // render the error page
  res.status(err.status || 500);
  res.render('error');
});

module.exports = app;

　　

/routes/all.js

var express = require('express');
var router = express.Router();
var bodyParser = require('body-parser')
var app = express();
var URL = require('url');

app.use(function(req, res, next) {
    res.header("Access-Control-Allow-Origin", "*");
    res.header("Access-Control-Allow-Headers", "Origin, X-Requested-With, Content-Type, Accept");
    next();
});
app.use(bodyParser.json());
app.use(bodyParser.urlencoded({ extended: false }));

router.get('/', function(req, res, next) {
    res.render('index', { title: 'Express' });
});

router.post('/login', function(req, res, next) {

    var params = req.body;

    var user = {}
    user.u = params.username
    var response = {status:1,data:user};
    res.send(JSON.stringify(response));

});

router.get('/login', function(req, res, next) {

    var params = URL.parse(req.url, true).query;

    console.log(params)

    var user = {}
    user.u = params.username

    var response = {status:2,data:user};
    res.send(JSON.stringify(response));

});

router.get('/users', function(req, res, next) {
    res.send('respond with a resource');
});

app.use('/', router)

module.exports = app;

　　

/package.json

{
  "name": "apiserver",
  "version": "0.0.0",
  "private": true,
  "scripts": {
    "start": "node ./bin/www"
  },
  "dependencies": {
    "cookie-parser": "~1.4.3",
    "debug": "~2.6.9",
    "express": "~4.15.5",
    "jade": "~1.11.0",
    "morgan": "~1.9.0",
    "serve-favicon": "~2.4.5"
  },
  "devDependencies": {
    "body-parser": "^1.18.2",
    "url": "^0.11.0"
  }
}