# 示例1 Echo
## 客户端代码
```html
WebSocket Demo
```
## 服务端代码
使用到的库
nodejs-websocket
- npm: https://www.npmjs.com/package/nodejs-websocket
- github: https://github.com/sitegui/nodejs-websocket
```bash
cnpm i nodejs-websocket -S
```
```js
// server.js
var ws = require("nodejs-websocket")
const PORT = 8080;
// 监听事件
var server = ws.createServer(function (connection) {
console.log("New connection")
// 接收客户端发送的数据
connection.on("text", function (data) {
console.log("Received "+data)
connection.sendText(data)
})
// 客户端断开
connection.on("close", function (code, reason) {
console.log("Connection closed")
})
// 客户端异常
connection.on("error", function (err) {
console.log('异常')
})
})
// 启动服务
server.listen(PORT, () => {
console.log(`Server started on port ${PORT}`)
})
```