nodejs搭建web服务器的方法

const request = require('request');
const express = require('express');
const path = require('path');

const app = express();

// 代理配置
const proxyTable = { 
 '/api': {
 target: 'http://localhost/api' 
 }
};
app.use(function(req, res,next) { 
 const url = req.url; 
 if (req.method == 'OPTIONS') { 
 console.log('options_url: ', url); 
 
 // 设置cors 跨域
 // res.header("Access-Control-Allow-Origin", req.headers.origin || '*');
 // res.header("Access-Control-Allow-Headers", "Content-Type, Authorization, X-Requested-With");
 // res.header("Access-Control-Allow-Methods", "PUT,POST,GET,DELETE,OPTIONS");

 // 设置 cookie
 // res.header("Access-Control-Allow-Credentials", true);
 
 res.status(200).send('OK'); 
 return;
 } 
 // console.log('req_url: ', url);
 next();
});

// 设置静态目录
app.use(express.static(path.join(__dirname, 'static')));

app.use('/', function(req, res) { 
 const url = req.url; 
 const proxy = Object.keys(proxyTable); 
 let not_found = true; 
 for (let index = 0; index < proxy.length; index++) { 
 const k = proxy[index]; 
 const i = url.indexOf(k); 
 if (i >= 0) { 
 not_found = false; 
 const element = proxyTable[k]; 
 const newUrl = element.target + url.slice(i+k.length);
 req.pipe(request({url: newUrl, timeout: 60000},(err)=>{
 if(err){ 
 console.log('error_url: ', err.code,url); 
 res.status(500).send('');
 } 
 })).pipe(res); 
 break;
 } 
 } 
 if(not_found) { 
 console.log('not_found_url: ', url);
 res.status(404).send('Not found');
 } else { 
 console.log('proxy_url: ', url);
 }
});

// 监听端口 
const PORT = 8080;
app.listen(PORT, () => { 
 console.log('HTTP Server is running on: http://localhost:%s', PORT);
});