NodeJS+Express+MongoDB开发api服务器

2017/10/20

关键字

NodeJS Express MongoDB

概述

之前用NodeJS搭建前端工作流，已经实现了本地静态服务器和代理服务器。配置代理服务器的目的就是为了调用其他服务器上的api接口，这次要自己实现一个api服务器。

准备工作

通过应用生成器工具 express 可以快速创建一个应用的骨架。

安装express：

npm install express-generator -g

初始化项目：

$ express myserver

  create : myserver
  create : myserver/package.json
  create : myserver/app.js
  create : myserver/public
  create : myserver/views
  create : myserver/views/index.jade
  create : myserver/views/layout.jade
  create : myserver/views/error.jade
  create : myserver/routes
  create : myserver/routes/index.js
  create : myserver/routes/users.js
  create : myserver/bin
  create : myserver/bin/www
  create : myserver/public/javascripts
  create : myserver/public/images
  create : myserver/public/stylesheets
  create : myserver/public/stylesheets/style.css

    install dependencies:
    $ cd myserver && npm install

    run the app:
    $ DEBUG=myserver:* npm start

启动服务器：

$ DEBUG=myserver:* npm start

> myserver@0.0.0 start /home/xu/www/myserver
> node ./bin/www

  myserver:server Listening on port 3000 +0ms

启动成功了，在写api接口前，先看下app.js这个文件

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

const index = require('./routes/index'); // 引入首页路由
const users = require('./routes/users'); // 引入用户接口路由

const app = express();

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

// 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')));

app.use('/', index); // 使用首页路由
app.use('/users', users); // 使用用户路由

// catch 404 and forward to error handler
app.use(function(req, res, next) {
  let 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;

再看下’./routes/index.js’和’./routes/users.js’两个文件

index.js

/* GET home page. */
router.get('/', function(req, res, next) {
  res.render('index', { title: 'Express' }); // 用到了'./views/index.jade'模板
});

users.js

/* GET users listing. */
router.get('/', function(req, res, next) {
  res.send('user api');
});

原理就是通过路由来判断用户请求，并给出响应。

第一个api接口

为了方便测试先用get请求。

需求：传入一个正确的id,返回对应的用户信息。

users.js

const express = require('express');
const router = express.Router();
const URL = require('url'); // 获取url参数，使用方法可查看NodeJS官方文档

/* GET users listing. */
router.get('/', function(req, res, next) {
  res.send('user api');
});

router.get('/getUserInfo', function(req, res, next) {
  let user = {};
  let response = {};
  let params = URL.parse(req.url, true).query;

  if(params.id == '1') {
    user.name = "Prosth";
    user.age = "12";
    user.city = "杭州市";
    response.status = 1;
    response.data = user;
  }else{    
    response.status = 1001;
    response.msg = 'User session ID does not exist';
  }

  res.send(JSON.stringify(response));
});

module.exports = router;

测试：

http://127.0.0.1:3000/users/getUserInfo
http://127.0.0.1:3000/users/getUserInfo?id=0

{"status":1001,"msg":"User session ID does not exist"}

http://127.0.0.1:3000/users/getUserInfo?id=1

{"status":1,"data":{"name":"Prosth","age":"12","city":"杭州市"}}

MongoDB数据库

未完待续