用nodejs搭建websocket服務(wù)器

更新時間：2017年01月23日 16:57:39 作者：stoneniqiu

這篇文章主要介紹了用nodejs搭建websocket服務(wù)器，小編覺得挺不錯的，現(xiàn)在分享給大家，也給大家做個參考。一起跟隨小編過來看看吧

簡單開始

2.安裝ws模塊

ws：是nodejs的一個WebSocket庫，可以用來創(chuàng)建服務(wù)。 https://github.com/websockets/ws

3.server.js

在項目里面新建一個server.js，創(chuàng)建服務(wù)，指定8181端口，將收到的消息log出來。

var WebSocketServer = require('ws').Server,
wss = new WebSocketServer({ port: 8181 });
wss.on('connection', function (ws) {
  console.log('client connected');
  ws.on('message', function (message) {
    console.log(message);
  });
});

4.建立一個client.html。

在頁面上建立一個WebSocket的連接。用send方法發(fā)送消息。

 var ws = new WebSocket("ws://localhost:8181");
  ws.onopen = function (e) {
    console.log('Connection to server opened');
  }
  function sendMessage() {
    ws.send($('#message').val());
  }

頁面：

<html xmlns="http://www.w3.org/1999/xhtml">
<head>
  <meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
  <title>WebSocket Echo Demo</title>
  <meta name="viewport" content="width=device-width, initial-scale=1"/>
  <link href="../bootstrap-3.3.5/css/bootstrap.min.css" rel="stylesheet" />
  <script src="../js/jquery-1.12.3.min.js"></script>
  <script src="../js/jquery-1.12.3.min.js"></script>
  <script src="../bootstrap-3.3.5/js/bootstrap.min.js"></script>
  <script>
  var ws = new WebSocket("ws://localhost:8181");
  ws.onopen = function (e) {
    console.log('Connection to server opened');
  }
  function sendMessage() {
    ws.send($('#message').val());
  }
  </script>
</head>

<body >
  <div class="vertical-center">
    <div class="container">
      <p>&nbsp;</p>
      <form role="form" id="chat_form" onsubmit="sendMessage(); return false;">
        <div class="form-group">
          <input class="form-control" type="text" name="message" id="message"
              placeholder="Type text to echo in here" value="" />
        </div>
        <button type="button" id="send" class="btn btn-primary"
            onclick="sendMessage();">
          Send!
        </button>
      </form>
    </div>
  </div>
</body>
</html>

運行之后如下，服務(wù)端即時獲得客戶端的消息。

模擬股票

上面的例子很簡單，只是為了演示如何運用nodejs的ws創(chuàng)建一個WebSocket服務(wù)器。且可以接受客戶端的消息。那么下面這個例子演示股票的實時更新?？头酥恍枰B接一次，服務(wù)器端會不斷地發(fā)送新數(shù)據(jù)，客戶端收數(shù)據(jù)后更新UI.頁面如下，有五只股票，開始和停止按鈕測試連接和關(guān)閉。

服務(wù)端：

1.模擬五只股票的漲跌。

var stocks = {
  "AAPL": 95.0,
  "MSFT": 50.0,
  "AMZN": 300.0,
  "GOOG": 550.0,
  "YHOO": 35.0
}
function randomInterval(min, max) {
  return Math.floor(Math.random() * (max - min + 1) + min);
}
var stockUpdater;
var randomStockUpdater = function() {
  for (var symbol in stocks) {
    if(stocks.hasOwnProperty(symbol)) {
      var randomizedChange = randomInterval(-150, 150);
      var floatChange = randomizedChange / 100;
      stocks[symbol] += floatChange;
    }
  }
  var randomMSTime = randomInterval(500, 2500);
  stockUpdater = setTimeout(function() {
    randomStockUpdater();
  }, randomMSTime);
}
randomStockUpdater();

2.連接建立之后就開始更新數(shù)據(jù)

wss.on('connection', function (ws) {
  var sendStockUpdates = function (ws) {
    if (ws.readyState == 1) {
      var stocksObj = {};
      for (var i = 0; i < clientStocks.length; i++) {
       var symbol = clientStocks[i];
        stocksObj[symbol] = stocks[symbol];
      }
      if (stocksObj.length !== 0) {
        ws.send(JSON.stringify(stocksObj));//需要將對象轉(zhuǎn)成字符串。WebSocket只支持文本和二進(jìn)制數(shù)據(jù)
        console.log("更新", JSON.stringify(stocksObj));
      }
      
    }
  }
  var clientStockUpdater = setInterval(function () {
    sendStockUpdates(ws);
  }, 1000);
  ws.on('message', function (message) {
    var stockRequest = JSON.parse(message);//根據(jù)請求過來的數(shù)據(jù)來更新。
    console.log("收到消息", stockRequest);
    clientStocks = stockRequest['stocks'];
    sendStockUpdates(ws);
  });

客戶端：

建立連接：

 var ws = new WebSocket("ws://localhost:8181");

onopen直接只有在連接成功后才會觸發(fā)，在這個時候?qū)⒖蛻舳诵枰埱蟮墓善卑l(fā)送給服務(wù)端。

var isClose = false;
  var stocks = {
    "AAPL": 0, "MSFT": 0, "AMZN": 0, "GOOG": 0, "YHOO": 0
  };
  function updataUI() {
    ws.onopen = function (e) {
      console.log('Connection to server opened');
      isClose = false;
      ws.send(JSON.stringify(stock_request));
      console.log("sened a mesg");
    }
    //更新UI
    var changeStockEntry = function (symbol, originalValue, newValue) {
      var valElem = $('#' + symbol + ' span');
      valElem.html(newValue.toFixed(2));
      if (newValue < originalValue) {
        valElem.addClass('label-danger');
        valElem.removeClass('label-success');
      } else if (newValue > originalValue) {
        valElem.addClass('label-success');
        valElem.removeClass('label-danger');
      }
    }
    // 處理受到的消息
    ws.onmessage = function (e) {
      var stocksData = JSON.parse(e.data);
      console.log(stocksData);
      for (var symbol in stocksData) {
        if (stocksData.hasOwnProperty(symbol)) {
          changeStockEntry(symbol, stocks[symbol], stocksData[symbol]);
          stocks[symbol] = stocksData[symbol];
        }
      }
    };
  }

  updataUI();

運行效果如下：只需要請求一次，數(shù)據(jù)就會不斷的更新，效果是不是很贊，不用輪詢，也不用長連接那么麻煩了。文章末尾會附上所有源碼。

（美股的漲跌和A股的顏色是反的，即紅跌綠漲）

實時聊天

上面的例子是連接建立之后，服務(wù)端不斷給客戶端發(fā)送數(shù)據(jù)。接下來例子是一個簡單的聊天室類的例子?？梢越⒍鄠€連接。

1.安裝node-uuid模塊，用來給每個連接一個唯一號。

2.服務(wù)端消息發(fā)送

消息類型分notification和message兩種，前者是提示信息，后者是聊天內(nèi)容。消息還包含一個id、昵稱和消息內(nèi)容。在上一節(jié)有學(xué)習(xí)到readyState有四個值，OPEN表示連接建立可以發(fā)送消息。如果頁面關(guān)閉了，為WebSocket.CLOSE。

function wsSend(type, client_uuid, nickname, message) {
  for (var i = 0; i < clients.length; i++) {
    var clientSocket = clients[i].ws;
    if (clientSocket.readyState === WebSocket.OPEN) {
      clientSocket.send(JSON.stringify({
        "type": type,
        "id": client_uuid,
        "nickname": nickname,
        "message": message
      }));
    }
  }
}

3.服務(wù)端處理連接

每新增加一個連接，都會發(fā)送一條匿名用戶的加入的提示消息，如果消息中帶有“/nick” 認(rèn)為這一個修改昵稱的消息。然后更新客戶端的昵稱。其他都會當(dāng)做聊天消息處理。

wss.on('connection', function(ws) {
  var client_uuid = uuid.v4();
  var nickname = "AnonymousUser" + clientIndex;
  clientIndex += 1;
  clients.push({ "id": client_uuid, "ws": ws, "nickname": nickname });
  console.log('client [%s] connected', client_uuid);
  var connect_message = nickname + " has connected";
  wsSend("notification", client_uuid, nickname, connect_message);
  console.log('client [%s] connected', client_uuid);
  ws.on('message', function(message) {
    if (message.indexOf('/nick') === 0) {
      var nickname_array = message.split(' ');
      if (nickname_array.length >= 2) {
        var old_nickname = nickname;
        nickname = nickname_array[1];
        var nickname_message = "Client " + old_nickname + " changed to " + nickname;
        wsSend("nick_update", client_uuid, nickname, nickname_message);
      }
    } else {
      wsSend("message", client_uuid, nickname, message);
    }
  });

處理連接關(guān)閉：

 var closeSocket = function(customMessage) {
    for (var i = 0; i < clients.length; i++) {
      if (clients[i].id == client_uuid) {
        var disconnect_message;
        if (customMessage) {
          disconnect_message = customMessage;
        } else {
          disconnect_message = nickname + " has disconnected";
        }
        wsSend("notification", client_uuid, nickname, disconnect_message);
        clients.splice(i, 1);
      }
    }
  };
  ws.on('close', function () {
    closeSocket();
  });

4.客戶端

沒有啟動時，頁面如下，change按鈕用來修改昵稱。

<div class="vertical-center">
    <div class="container">
      <ul id="messages" class="list-unstyled"></ul>
      <hr/>
      <form role="form" id="chat_form" onsubmit="sendMessage(); return false;">
        <div class="form-group">
          <input class="form-control" type="text" id="message" name="message"
              placeholder="Type text to echo in here" value="" autofocus/>
        </div>
        <button type="button" id="send" class="btn btn-primary"
            onclick="sendMessage();">
          Send Message
        </button>

      </form>
      <div class="form-group"><span>nikename：</span><input id="name" type="text" /> <button class="btn btn-sm btn-info" onclick="changName();">change</button></div>
    </div>
  </div>

js:

  //建立連接
    var ws = new WebSocket("ws://localhost:8181");
    var nickname = "";
    ws.onopen = function (e) {
      console.log('Connection to server opened');
    }
    //顯示
    function appendLog(type, nickname, message) {
      if (typeof message == "undefined") return;
      var messages = document.getElementById('messages');
      var messageElem = document.createElement("li");
      var preface_label;
      if (type === 'notification') {
        preface_label = "<span class=\"label label-info\">*</span>";
      } else if (type == 'nick_update') {
        preface_label = "<span class=\"label label-warning\">*</span>";
      } else {
        preface_label = "<span class=\"label label-success\">"
        + nickname + "</span>";
      }
      var message_text = "<h2>" + preface_label + "&nbsp;&nbsp;"
      + message + "</h2>";
      messageElem.innerHTML = message_text;
      messages.appendChild(messageElem);
    }
    //收到消息處理
    ws.onmessage = function (e) {
      var data = JSON.parse(e.data);
      nickname = data.nickname;
      appendLog(data.type, data.nickname, data.message);
      console.log("ID: [%s] = %s", data.id, data.message);
    }
    ws.onclose = function (e) {
      appendLog("Connection closed");
      console.log("Connection closed");
    }
    //發(fā)送消息
    function sendMessage() {
      var messageField = document.getElementById('message');
      if (ws.readyState === WebSocket.OPEN) {
        ws.send(messageField.value);
      }
      messageField.value = '';
      messageField.focus();
    }
    //修改名稱
    function changName() {
      var name = $("#name").val();
      if (ws.readyState === WebSocket.OPEN) {
        ws.send("/nick " + name);
      }
    }

運行結(jié)果：

頁面關(guān)閉之后，連接馬上斷開。