node使用Koa2搭建web项目的方法(2)

日期：2020-05-11 栏目：程序人生 浏览：次

自动扫描controller包实现方法如下

const fs = require('fs');
const router = require('koa-router')();

function addMapping(router, mapping) {
  for (var url in mapping) {
    if (url.startsWith('GET ')) {
      var path = url.substring(4);
      router.get(path, mapping[url]);
      console.log(`register URL mapping: GET ${path}`);
    } else if (url.startsWith('POST ')) {
      var path = url.substring(5);
      router.post(path, mapping[url]);
      console.log(`register URL mapping: POST ${path}`);
    } else if (url.startsWith('PUT ')) {
      var path = url.substring(4);
      router.put(path, mapping[url]);
      console.log(`register URL mapping: PUT ${path}`);
    } else if (url.startsWith('DELETE ')) {
      var path = url.substring(7);
      router.del(path, mapping[url]);
      console.log(`register URL mapping: DELETE ${path}`);
    } else {
      console.log(`invalid URL: ${url}`);
    }
  }
}

function addControllers(router, dir) {
  fs.readdirSync(__dirname + '/' + dir).filter((f) => {
    return f.endsWith('.js');
  }).forEach((f) => {
    console.log(`process controller: ${f}...`);
    let mapping = require(__dirname + '/' + dir + '/' + f);
    addMapping(router, mapping);
  });
}

module.exports = function (dir) {
  var controllersDir = dir || 'controller';
  addControllers(router, controllersDir);
  return router.routes();
};

2.4. 控制器

[userController.js]

***Controller.js是用来处理具体请求信息以及返回数据的，userController.js中处理了GET请求获取用户信息，POST请求保存用户信息

const userService = require('./../service/userService.js');

var getUserinfo = (ctx, next) => {
  let query = ctx.query;
  let userId = query.id;
  let userInfo = userService.getUserById(userId);

  let html = '<html><body>'
    + '<div> userinfo: ' + userInfo + '</div>'
    + '</body></html>';
  ctx.response.type ='text/html';
  ctx.response.body = html;
};

var saveUserinfo = (ctx, next) => {
  const requestString = ctx.data;
  //TODO数据处理
  Console.log(requestString);
};

module.exports = {
  'GET /getUserinfo': getUserinfo,
  'POST /saveUserinfo': saveUserinfo
};

2.5. 数据处理

[userService.js]

处理封装从***Dao.js获取到的数据返回给Controller

const userDao = require('./../dao/userDao.js');

var getUserById = async (userId) => {
  var users = userDao.getUserById(userId);
  var responseContent = '';
  for(let user of users) {
    reaponseContent += '姓名：' + user.name + ' |';
    reaponseContent += '年龄：' + user.age + ' |';
    reaponseContent += '身高：' + user.height + '<br />';
  }
  return responseContent;
}

module.exports = {
  getUserById : getUserById
};

2.6. 数据获取