Node.js是一个基于Chrome V8引擎的JavaScript运行环境，它使得JavaScript可以在服务器端运行。以下是一些Node.js的应用场景：
- 快速构建高性能的动态WEB应用
- 构建命令行工具和程序
- 实时Web应用(如多人游戏)
- 实时通讯(如WebSocket服务器)
- 创建TCP/UDP服务器
- 定时任务和调度(如cron job)
- 解析和生成PDF文件
- 数据抓取和处理
- 提供RESTful API
- 开发桌面应用(使用Node-webkit或Electron)
解决方案和示例代码：
- 快速构建高性能的动态WEB应用
const http = require('http');
http.createServer((req, res) => {
res.writeHead(200, {'Content-Type': 'text/plain'});
res.end('Hello World\n');
}).listen(3000, () => {
console.log('Server running at http://127.0.0.1:3000/');
});- 构建命令行工具和程序
#!/usr/bin/env node
console.log('Hello, world!');- 实时Web应用(如多人游戏)
const express = require('express');
const http = require('http');
const WebSocket = require('ws');
const app = express();
app.use(express.static('public'));
const server = http.createServer(app);
const wss = new WebSocket.Server({ server });
wss.on('connection', function connection(ws) {
ws.on('message', function incoming(message) {
console.log('received: %s', message);
});
ws.send('something');
});
server.listen(3000, function listening() {
console.log('Listening on %d', server.address().port);
});- 实时通讯(如WebSocket服务器)
const WebSocket = require('ws');
const wss = new WebSocket.Server({ port: 8080 });
wss.on('connection', function connection(ws) {
ws.on('message', function incoming(message) {
console.log('received: %s', message);
});
ws.send('something');
});- 创建TCP/UDP服务器
const dgram = require('dgram');
const server = dgram.createSocket('udp4');
server.on('message', (msg, rinfo) => {
console.log(`server got: ${msg} from ${rinfo.address}:${rinfo.port}`);
});
server.on('listening', () => {
const address = server.address();
console.log(`server listening ${address.address}:${address.port}`);
});
server.bind(41234);- 定时任务和调度(如cron job)
const CronJob = require('cron').CronJob;
new CronJob({
cronTime: '* * * * * *',
onTick: function() {
console.log('you task');