pom.xml
<dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-websocket</artifactId> </dependency>websocket配置（没有此配置会导致连接websocket失败）
package com.websocket.websocket.config; import org.springframework.context.annotation.Bean; import org.springframework.context.annotation.Configuration; import org.springframework.web.socket.server.standard.ServerEndpointExporter; @Configuration public class WebSocketConfig { @Bean public ServerEndpointExporter serverEndpointExporter() { return new ServerEndpointExporter(); } }package com.websocket.websocket.Controller; import org.springframework.stereotype.Component; import javax.websocket.*; import javax.websocket.server.ServerEndpoint; import java.io.IOException; import java.util.concurrent.CopyOnWriteArraySet; import java.util.concurrent.atomic.AtomicInteger; @ServerEndpoint("/ws/asset") @Component public class WebSocketController { private static final AtomicInteger OnlineCount = new AtomicInteger(0); // concurrent包的线程安全Set，用来存放每个客户端对应的Session对象。 private static CopyOnWriteArraySet<Session> SessionSet = new CopyOnWriteArraySet<Session>(); /** * 连接建立成功调用的方法 */ @OnOpen public void onOpen(Session session) { SessionSet.add(session); int cnt = OnlineCount.incrementAndGet(); // 在线数加1 System.out.println("有连接加入，当前连接数为：" + cnt); SendMessage(session, "连接成功"); } /** * 连接关闭调用的方法 */ @OnClose public void onClose(Session session) { SessionSet.remove(session); int cnt = OnlineCount.decrementAndGet(); System.out.println("有连接关闭，当前连接数为：" + cnt); } /** * 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 */ @OnMessage public void onMessage(String message, Session session) { System.out.println("来自客户端的消息：" + message); SendMessage(session, "收到消息，消息内容："+message); } /** * 出现错误 * @param session * @param error */ @OnError public void onError(Session session, Throwable error) { System.out.println("发生错误：" + error.getMessage() + "，Session ID：" + session.getId()); error.printStackTrace(); } /** * 发送消息，实践表明，每次浏览器刷新，session会发生变化。 * @param session * @param message */ public static void SendMessage(Session session, String message) { try { session.getBasicRemote().sendText(String.format("%s (From Server，Session ID=%s)",message,session.getId())); } catch (IOException e) { System.out.println("发送消息出错：" + e.getMessage()); e.printStackTrace(); } } /** * 群发消息 * @param message * @throws IOException */ public static void BroadCastInfo(String message) throws IOException { for (Session session : SessionSet) { if(session.isOpen()){ SendMessage(session, message); } } } /** * 指定Session发送消息 * @param sessionId * @param message * @throws IOException */ public static void SendMessage(String sessionId,String message) throws IOException { Session session = null; for (Session s : SessionSet) { if(s.getId().equals(sessionId)){ session = s; break; } } if(session!=null){ SendMessage(session, message); } else { System.out.println("没有找到你指定ID的会话：" + sessionId); } } }
html（客户端）
<!DOCTYPE HTML> <html> <head> <meta charset="UTF-8"> <title>My WebSocket</title> </head> <body> Welcome<br/> <input id="text" type="text" /><button onclick="send()">Send</button> <button onclick="closeWebSocket()">Close</button> <div id="message"> </div> </body> <script type="text/javascript"> var websocket = null; //判断当前浏览器是否支持WebSocket if('WebSocket' in window){ websocket = new WebSocket("ws://localhost:8080/ws/asset"); } else{ alert('Not support websocket') } //连接发生错误的回调方法 websocket.onerror = function(){ setMessageInnerHTML("error"); }; //连接成功建立的回调方法 websocket.onopen = function(event){ setMessageInnerHTML("open"); } //接收到消息的回调方法 websocket.onmessage = function(event){ setMessageInnerHTML(event.data); } //连接关闭的回调方法 websocket.onclose = function(){ setMessageInnerHTML("close"); } //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(){ websocket.close(); } //将消息显示在网页上 function setMessageInnerHTML(innerHTML){ document.getElementById('message').innerHTML += innerHTML + '<br/>'; } //关闭连接 function closeWebSocket(){ websocket.close(); } //发送消息 function send(){ var message = document.getElementById('text').value; websocket.send(message); } </script> </html>
