前台页面：
<html>
<head>
<meta http-equiv="Content-Type" content="text/html;charset=utf-8">
<meta http-equiv="X-UA-Compatible" content="IE=edge,chrome=1">
<title>Web sockets test</title>
<style type="text/css">
.container {
font-family: "Courier New";
680px;
height: 300px;
overflow: auto;
border: 1px solid black;
}
.LockOff {
display: none;
visibility: hidden;
}
.LockOn {
display: block;
visibility: visible;
position: absolute;
z-index: 999;
top: 0px;
left: 0px;
1024%;
height: 768%;
background-color: #ccc;
text-align: center;
padding-top: 20%;
filter: alpha(opacity=75);
opacity: 0.75;
}
</style>
<script src="jquery-min.js" type="text/javascript"></script>
<script type="text/javascript">
var ws;
var SocketCreated = false;
var isUserloggedout = false;
function lockOn(str) {
var lock = document.getElementById('skm_LockPane');
if (lock)
lock.className = 'LockOn';
lock.innerHTML = str;
}
function lockOff() {
var lock = document.getElementById('skm_LockPane');
lock.className = 'LockOff';
}
function ToggleConnectionClicked() {
if (SocketCreated && (ws.readyState == 0 || ws.readyState == 1)) {
lockOn("离开聊天室...");
ws.send("【" + document.getElementById("txtName").value + "】离开了聊天室！");
SocketCreated = false;
isUserloggedout = true;
ws.close();
} else {
lockOn("进入聊天室...");
Log("准备连接到聊天服务器 ...");
try {
if ("WebSocket" in window) {
ws = new WebSocket("ws://" + document.getElementById("Connection").value);
}
else if ("MozWebSocket" in window) {
ws = new MozWebSocket("ws://" + document.getElementById("Connection").value);
}
SocketCreated = true;
isUserloggedout = false;
} catch (ex) {
Log(ex, "ERROR");
return;
}
document.getElementById("ToggleConnection").innerHTML = "断开";
ws.onopen = WSonOpen;
ws.onmessage = WSonMessage;
ws.onclose = WSonClose;
ws.onerror = WSonError;
}
};
function WSonOpen() {
lockOff();
Log("连接已经建立。", "OK");
$("#SendDataContainer").show();
ws.send("【"+document.getElementById("txtName").value+"】进入了聊天室!");
};
function WSonMessage(event) {
// console.log(event)
// Log(event.data);
var data = event.data;
var obj = JSON.parse(data);
if ("1" == obj.code) { // 客户端信息回显
Log(obj.data);
} else if ("0" == obj.code) { // 在线人数更新
$("#logCount").text(obj.data);
}
};
function WSonClose() {
lockOff();
if (isUserloggedout)
Log("【" + document.getElementById("txtName").value + "】离开了聊天室！");
document.getElementById("ToggleConnection").innerHTML = "连接";
$("#SendDataContainer").hide();
};
function WSonError() {
lockOff();
Log("远程连接中断。", "ERROR");
};
function SendDataClicked() {
if (document.getElementById("DataToSend").value.trim() != "") {
ws.send(document.getElementById("txtName").value + "说 :"" + document.getElementById("DataToSend").value + """);
document.getElementById("DataToSend").value = "";
}
};
function Log(Text, MessageType) {
if (MessageType == "OK") Text = "<span style='color: green;'>" + Text + "</span>";
if (MessageType == "ERROR") Text = "<span style='color: red;'>" + Text + "</span>";
document.getElementById("LogContainer").innerHTML = document.getElementById("LogContainer").innerHTML + Text + "<br />";
var LogContainer = document.getElementById("LogContainer");
LogContainer.scrollTop = LogContainer.scrollHeight;
};
$(document).ready(function () {
$("#SendDataContainer").hide();
var WebSocketsExist = true;
try {
var dummy = new WebSocket("ws://localhost:8080/test");
} catch (ex) {
try {
webSocket = new MozWebSocket("ws://localhost:8080/test");
}
catch (ex) {
WebSocketsExist = false;
}
}
if (WebSocketsExist) {
Log("您的浏览器支持WebSocket. 您可以尝试连接到聊天服务器!", "OK");
document.getElementById("Connection").value = "localhost:8080/wschat";
} else {
Log("您的浏览器不支持WebSocket。请选择其他的浏览器再尝试连接服务器。", "ERROR");
document.getElementById("ToggleConnection").disabled = true;
}
$("#DataToSend").keypress(function (evt) {
if (evt.keyCode == 13) {
$("#SendData").click();
evt.preventDefault();
}
})
//监听窗口关闭事件，当窗口关闭时，主动去关闭websocket连接，防止连接还没断开就关闭窗口，server端会抛异常。
window.onbeforeunload = function () {
ws.close();
}
});
</script>
</head>
<body>
<div id="skm_LockPane" class="LockOff"></div>
<form id="form1" runat="server">
<h1>Web Socket 聊天室</h1>
<br/>
<div>
按下连接按钮，会通过WebSocket发起一个到聊天浏览器的连接。
</div>
服务器地址: <input type="text" id="Connection"/> 用户名： <input type="text" id="txtName" value="黄晓安"/>
<button id='ToggleConnection' type="button" onclick='ToggleConnectionClicked();'>连接</button>
在线人数：<span id="logCount">0</span>
<br/>
<br/>
<div id='LogContainer' class='container'></div>
<br/>
<div id='SendDataContainer'>
<input type="text" id="DataToSend" size="88"/>
<button id='SendData' type="button" onclick='SendDataClicked();'>发送</button>
</div>
<br/>
</form>
</body>
</html>后台代码：
package com.uptop.websocket;
import com.alibaba.fastjson.JSON;
import com.uptop.entity.ResultVo;
import javax.websocket.*;
import javax.websocket.server.ServerEndpoint;
import java.io.IOException;
import java.util.concurrent.CopyOnWriteArraySet;
/**
* websocket 聊天室
*
* @author Administrator
* @create 2018-02-05 15:17
*/
@ServerEndpoint("/wschat")
public class WebSocketChat {
//静态变量，用来记录当前在线连接数。应该把它设计成线程安全的。
private static int onlineCount = 0;
//concurrent包的线程安全Set，用来存放每个客户端对应的MyWebSocket对象。若要实现服务端与单一客户端通信的话，可以使用Map来存放，其中Key可以为用户标识
public static CopyOnWriteArraySet<WebSocketChat> webSocketSet = new CopyOnWriteArraySet<WebSocketChat>();
//与某个客户端的连接会话，需要通过它来给客户端发送数据
private Session session;
/**
* 连接建立成功调用的方法
*
* @param session 可选的参数。session为与某个客户端的连接会话，需要通过它来给客户端发送数据
*/
@OnOpen
public void onOpen(Session session) {
this.session = session;
webSocketSet.add(this); //加入set中
addOnlineCount(); //在线数加1
// 发送在线人数数据
ResultVo resultVo = new ResultVo("0",this.onlineCount,"from server");
sendMsg(JSON.toJSONString(resultVo));
System.out.println("有新连接加入！当前在线人数为" + getOnlineCount());
}
/**
* 连接关闭调用的方法
*/
@OnClose
public void onClose() {
webSocketSet.remove(this); //从set中删除
subOnlineCount(); //在线数减1
// 发送在线人数数据
ResultVo resultVo = new ResultVo("0",this.onlineCount,"from server");
sendMsg(JSON.toJSONString(resultVo));
System.out.println("有一连接关闭！当前在线人数为" + getOnlineCount());
}
/**
* 收到客户端消息后调用的方法
*
* @param message 客户端发送过来的消息
* @param session 可选的参数
*/
@OnMessage
public void onMessage(String message, Session session) {
System.out.println("来自客户端的消息:" + message);
// 封装客户端消息
ResultVo resultVo = new ResultVo("1",message,"from client");
String jsonStr = JSON.toJSONString(resultVo);
//群发消息
for (WebSocketChat item : webSocketSet) {
try {
item.sendMessage(jsonStr);
} catch (IOException e) {
e.printStackTrace();
continue;
}
}
}
/**
* 发生错误时调用
*
* @param session
* @param error
*/
@OnError
public void onError(Session session, Throwable error) {
System.out.println("发生错误");
error.printStackTrace();
}
/**
* 这个方法与上面几个方法不一样。没有用注解，是根据自己需要添加的方法。
*
* @param message
* @throws IOException
*/
public void sendMessage(String message) throws IOException {
this.session.getBasicRemote().sendText(message);
}
public static synchronized int getOnlineCount() {
return onlineCount;
}
public static synchronized void addOnlineCount() {
WebSocketChat.onlineCount++;
}
public static synchronized void subOnlineCount() {
WebSocketChat.onlineCount--;
}
public static void sendMsg(String msg) {
for (WebSocketChat item : webSocketSet) {
try {
item.sendMessage(msg);
} catch (IOException e) {
e.printStackTrace();
continue;
}
}
}
}
效果图：
注：本案例参考ibm文库案例的前台页面，后台使用Java实现。