node模拟socket

什么是Socket?
网络上的两个程序通过一个双向的通信连接实现数据的交换，这个连接的一端称为一个socket。

Socket通信流程

基于net模块实现socket

服务端SocketServer.js

var net = require('net')

// 声明一个客户端socket
var client = new net.Socket()

client.setEncoding = 'UTF-8'

// 连接服务器
client.connect(9000, '127.0.0.1', function () {
  client.write('您好')
})

// 客户端接收服务端数据
client.on('data', function (data) {
  console.log('服务端传来：' + data)
  say()
})

// 客户端关闭
client.on('close', function () {
  console.log('connection closed');
})

// 定义输入界面
var readline = require('readline')

var r = readline.createInterface({
  input: process.stdin,
  output: process.stdout
})

function say() {
  r.question('请输入：', (inputStr) => {
    if (inputStr == 'bye') {
      client.destroy()
      r.close()
    } else {
      client.write(inputStr + '
')
    }
  })
}

View Code

客户端SocketClient.js

var net = require('net')

var chatServer = net.createServer()

// client 对象集合
var clientMap = new Object()

var i = 0

// 创建一个连接
chatServer.on('connection', function (client) {
  console.log('客户端有人连接~')

  // 用自然数记录用户的名字
  client.name = ++i

  // 记录client对象
  clientMap[client.name] = client

  // 获取用户端发送来的数据
  client.on('data', function (data) {
    console.log('客户端传来：' + data)
    broadcast(data, client)
  })

  // 错误处理
  client.on('error', function (err) {
    // console.log(err);
    client.end()
  })

  // 客户端关闭处理
  client.on('close', function (data) {
    delete clientMap[client.name]
    broadcast(client.name + '下线了', client)
  })

})

// 服务端广播数据给客户端
function broadcast(data, client) {
  for (var key in clientMap) {
    // 发送数据
    clientMap[key].write(client.name + ' 说：' + data + '
')
  }
}

// 监听端口
chatServer.listen(9000)

View Code

启动服务端：

node SocketServer.js

使用多个窗口启动客户端：

node SocketClient.js

模拟websocket

服务端

WsServer.js

// 服务创建
var WebsocketServer = require('ws').Server
wss = new WebsocketServer({port: 9000})

var clientMap = new Object()
var i = 0

wss.on('connection', function (ws) {
  console.log(ws + '上线了');
  ws.name = ++i

  clientMap[ws.name] = ws

  // 接收客户数据
  ws.on('message', function (msg) {
    broadcast(msg, ws)
  })

  // 客户端关闭监听
  ws.on('close', function () {
    delete clientMap[ws.name]
    console.log(ws.name + '离开');
  })
})

function broadcast(msg, ws) {
  for (var key in clientMap) {
    clientMap[key].send(ws.name + '说' + msg)
  }
}

View Code

客户端：

WsClient.js

var ws = new WebSocket('ws://127.0.0.1:9000/')

ws.onopen = function () {
  ws.send('大家好')
}

ws.onmessage = function (event) {
  var chatroom = document.querySelector('#chatroom')
  chatroom.innerHTML += '<br />' + event.data
}

ws.onclose = function () {
  console.log('Closed');
}

ws.onerror = function (err) {
  console.log(err);
}

View Code

index.html

<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <meta http-equiv="X-UA-Compatible" content="ie=edge">
  <title>Document</title>
  <style>
    #chatroom {
      width: 400px;
      height: 300px;
      overflow: auto;
      border: 1px solid blue;
    }
  </style>
</head>
<body>
  <h1>WebSocket</h1>
  <div id="chatroom"></div>
  <input type="text" name="sayinput" id="sayinput" value="">
  <input type="button" name="send" id="send" value="发送">

  <script src="./WsClient.js"></script>
  <script>
    function send() {
      var sayinput = document.querySelector('#sayinput')
      ws.send(sayinput.value)
      sayinput.value = ''
    }
    document.querySelector('#send').onclick = function () {
      send()
    }
    document.body.onkeyup = function (event) {
      if (event.keyCode == 13) {
        send()
      }
    }
  </script>
</body>
</html>

View Code

socket.io的使用

SocketIoServer.js

var http = require('http')
var app = http.createServer()
var io = require('socket.io')(app);

app.listen(9001);

io.on('connection', function (socket) {
  //socket.name = ++i
  //onlineusers[socket.name] = socket
  socket.on('my other event', function (data) {
    // for (var key in onlineusers) {
    //   onlineusers[key].emit('news', { msg: data.my })
    // }
    socket.emit('news', { msg: data.my });
    socket.broadcast.emit('news', { msg: data.my });
  });
});

View Code

index.html

<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <meta http-equiv="X-UA-Compatible" content="ie=edge">
  <title>Socket.io</title>
  <style>
    #chatroom {
      width: 400px;
      height: 300px;
      overflow: auto;
      border: 1px solid blue;
    }
  </style>
</head>
<body>
  <h1>Socket.io</h1>
  <div id="chatroom"></div>
  <input type="text" name="sayinput" id="sayinput" value="">
  <input type="button" name="send" id="send" value="发送">

  <script src="./socket.io.js"></script>
  <script>
    var socket = io('http://localhost:9001');
    socket.on('news', function (data) {
      document.querySelector('#chatroom').innerHTML += data.msg + "<br/>"
    });

    function send() {
      var sayinput = document.querySelector('#sayinput')
      socket.emit('my other event', { my: sayinput.value });
      sayinput.value = ''
    }
    document.querySelector('#send').onclick = function () {
      send()
    }
    document.body.onkeyup = function (event) {
      if (event.keyCode == 13) {
        send()
      }
    }
  </script>
</body>
</html>

View Code

express脚手架（ express-generator）+socketio

　　https://my.oschina.net/freddon/blog/529599