var websocket =null;
var host = document.location.host;
var username ="${loginUsername}";// 獲得當前登錄人員的userName
// alert(username)
//判斷當前瀏覽器是否支持WebSocket
if('WebSocket'in window) {
alert("瀏覽器支持Websocket")
websocket =newWebSocket('ws://'+host+'/mm-dorado/webSocket/'+username);
}else{
alert('當前瀏覽器 Not support websocket')
}

//連接發生錯誤的回調方法
websocket.onerror = function() {
　　alert("WebSocket連接發生錯誤")
setMessageInnerHTML("WebSocket連接發生錯誤");
};

//連接成功建立的回調方法
websocket.onopen = function() {
　　alert("WebSocket連接成功")
setMessageInnerHTML("WebSocket連接成功");
}

//接收到消息的回調方法
websocket.onmessage = function(event) {
alert("接收到消息的回調方法")
alert("這是后臺推送的消息："+event.data);
　　　　 websocket.close();
　　　　alert("webSocket已關閉！")
}

//連接關閉的回調方法
websocket.onclose = function() {
setMessageInnerHTML("WebSocket連接關閉");
}

//監聽窗口關閉事件，當窗口關閉時，主動去關閉websocket連接，防止連接還沒斷開就關閉窗口，server端會拋異常。
window.onbeforeunload = function() {
closeWebSocket();
}

//關閉WebSocket連接
function closeWebSocket() {
websocket.close();
}

//將消息顯示在網頁上
function setMessageInnerHTML(innerHTML) {
document.getElementById('message').innerHTML += innerHTML +'<br/>';
}

packagecom.mes.util;

importjava.io.IOException;
importjava.util.Map;
importjava.util.concurrent.ConcurrentHashMap;

importjavax.websocket.OnClose;
importjavax.websocket.OnError;
importjavax.websocket.OnMessage;
importjavax.websocket.OnOpen;
importjavax.websocket.Session;
importjavax.websocket.server.PathParam;
importjavax.websocket.server.ServerEndpoint;

importorg.springframework.stereotype.Component;
importorg.springframework.stereotype.Service;

importcom.google.gson.JsonObject;

importnet.sf.json.JSONObject;
@ServerEndpoint("/webSocket/{username}")
publicclassWebSocket {
privatestaticintonlineCount =0;
privatestaticMap<String, WebSocket> clients =newConcurrentHashMap<String, WebSocket>();
privateSession session;
privateString username;

@OnOpen
publicvoidonOpen(@PathParam("username") String username, Session session)throwsIOException {

this.username = username;
this.session = session;

addOnlineCount();
clients.put(username,this);
System.out.println("已連接");
}

@OnClose
publicvoidonClose()throwsIOException {
clients.remove(username);
subOnlineCount();
}

@OnMessage
publicvoidonMessage(String message)throwsIOException {

JSONObject jsonTo = JSONObject.fromObject(message);
String mes = (String) jsonTo.get("message");

if(!jsonTo.get("To").equals("All")){
sendMessageTo(mes, jsonTo.get("To").toString());
}else{
sendMessageAll("給所有人");
}
}

@OnError
publicvoidonError(Session session, Throwable error) {
error.printStackTrace();
}

publicvoidsendMessageTo(String message, String To)throwsIOException {
// session.getBasicRemote().sendText(message);
//session.getAsyncRemote().sendText(message);
for(WebSocket item : clients.values()) {
if(item.username.equals(To) )
item.session.getAsyncRemote().sendText(message);
}
}

publicvoidsendMessageAll(String message)throwsIOException {
for(WebSocket item : clients.values()) {
item.session.getAsyncRemote().sendText(message);
}
}

publicstaticsynchronizedintgetOnlineCount() {
returnonlineCount;
}

publicstaticsynchronizedvoidaddOnlineCount() {
WebSocket.onlineCount++;
}

publicstaticsynchronizedvoidsubOnlineCount() {
WebSocket.onlineCount--;
}

publicstaticsynchronizedMap<String, WebSocket> getClients() {
returnclients;
}
}

WebSocket ws =newWebSocket();
JSONObject jo =newJSONObject();
jo.put("message","這是后臺返回的消息！");
jo.put("To",invIO.getIoEmployeeUid());
ws.onMessage(jo.toString());

<!-- webSocket 開始-->
<dependency>
<groupId>javax.websocket</groupId>
<artifactId>javax.websocket-api</artifactId>
<version>1.1</version>
<scope>provided</scope>
</dependency>

<dependency>
<groupId>javax</groupId>
<artifactId>javaee-api</artifactId>
<version>7.0</version>
<scope>provided</scope>
</dependency>
<!-- webSocket 結束-->