ztj_03 koa改造工程

ztj_03 koa改造工程

将项目目录整理一下，顺便加深理解

1.新增koa-json中间件

json解析

npm install koa-json --save

2.新增koa-onerror中间件

对错误进行统一处理

npm install koa-onerror --save

3.新增koa-static中间件

静态服务中间件

npm install koa-static--save

4.新增koa-logger中间件

日志模块

npm install koa-logger--save

---

增加中间件后的app.js

const Koa = require('koa');
const app = new Koa();
const json = require('koa-json');
const router = require('./router');
const bodyParser = require('koa-bodyparser');
const onerror = require('koa-onerror');
const koaStatic = require('koa-static');
const logger = require('koa-logger');

//错误处理
onerror(app);

app.use(bodyParser());
app.use(logger());
app.use(json());
app.use(koaStatic(__dirname + '/public'));

// logger日志
app.use(async (ctx, next) => {
    const start = new Date();
    await next();
    const ms = new Date() - start;
    console.log(`${ctx.method} ${ctx.url} - ${ms}ms`)
});

app
    .use(router.routes())
    .use(router.allowedMethods());

app.on('error', (err, ctx) => {
    console.error('server error', err, ctx)
});

module.exports = app;

---

5.完善目录

1.新建router目录，保存router相关文件
2.新建public目录，静态资源目录
3.新建bin目录，新建www文件做启动文件
www文件代码,这段是koa项目生成器的启动文件代码

#!/usr/bin/env node

/**
 * Module dependencies.
 */

var app = require('../app');
var debug = require('debug')('ztj:server');
var http = require('http');

/**
 * Get port from environment and store in Express.
 */

var port = normalizePort(process.env.PORT || '3000');
// app.set('port', port);

/**
 * Create HTTP server.
 */

var server = http.createServer(app.callback());

/**
 * Listen on provided port, on all network interfaces.
 */

server.listen(port);
server.on('error', onError);
server.on('listening', onListening);

/**
 * Normalize a port into a number, string, or false.
 */

function normalizePort(val) {
  var port = parseInt(val, 10);

  if (isNaN(port)) {
    // named pipe
    return val;
  }

  if (port >= 0) {
    // port number
    return port;
  }

  return false;
}

/**
 * Event listener for HTTP server "error" event.
 */

function onError(error) {
  if (error.syscall !== 'listen') {
    throw error;
  }

  var bind = typeof port === 'string'
    ? 'Pipe ' + port
    : 'Port ' + port;

  // handle specific listen errors with friendly messages
  switch (error.code) {
    case 'EACCES':
      console.error(bind + ' requires elevated privileges');
      process.exit(1);
      break;
    case 'EADDRINUSE':
      console.error(bind + ' is already in use');
      process.exit(1);
      break;
    default:
      throw error;
  }
}

/**
 * Event listener for HTTP server "listening" event.
 */

function onListening() {
  var addr = server.address();
  var bind = typeof addr === 'string'
    ? 'pipe ' + addr
    : 'port ' + addr.port;
  debug('Listening on ' + bind);
}

最后修改下package.json的启动脚本

  "scripts": {
    "start": "node bin/www",
    "dev": "./node_modules/.bin/nodemon bin/www",
    "prd": "pm2 start bin/www",
    "test": "echo \"Error: no test specified\" && exit 1"
  },