websocket完整demo

package com.web.demo; import java.util.HashMap; import java.util.Iterator; import java.util.Map; import javax.websocket.OnClose; import javax.websocket.OnError; import javax.websocket.OnMessage; import javax.websocket.OnOpen; import javax.websocket.Session; import javax.websocket.server.PathParam; import javax.websocket.server.ServerEndpoint; @ServerEndpoint("/websocket/{userId}") public class WebSocketTest { private static Map<String, Session> sessionMap=new HashMap<String, Session>();//在线的客户端session集合，只在第一次new的时候初始化。 /** * 接收信息事件 * @param message 客户端发来的消息 * @param session 当前会话 */ @OnMessage public void onMessage(String message,Session session,@PathParam(value="userId")String userId)throws Exception { try { Iterator<String> it = sessionMap.keySet().iterator(); //循环给每个客户端发送信息 while(it.hasNext()){ String key = (String) it.next(); Session value = sessionMap.get(key); value.getBasicRemote().sendText(message); } System.out.println("用户"+userId+"说："+message+"。"); System.out.println("当前在线人数："+sessionMap.size()); } catch (Exception e) { System.out.println("接收消息事件异常!"); } } /** * 打开连接事件 * @throws Exception */ @OnOpen public void onOpen(Session session,@PathParam(value="userId")String userId) throws Exception { System.out.println("打开连接成功！"); sessionMap.put(userId, session); System.out.println("用户"+userId+"进来了。。。"); System.out.println("当前在线人数："+sessionMap.size()); } /** * 关闭连接事件 */ @OnClose public void onClose(Session session,@PathParam(value="userId")String userId) { System.out.println("关闭连接成功！"); System.out.println("用户"+userId+"离开了。。。"); sessionMap.remove(userId); System.out.println("当前在线人数："+sessionMap.size()); } /** * 错误信息响应事件 * @param session * @param throwable */ @OnError public void OnError(Session session,Throwable throwable,@PathParam(value="userId")String userId) { System.out.println("异常："+throwable.getMessage()); System.out.println("用户"+userId+"的连接出现了错误。。。"); System.out.println("当前在线人数："+sessionMap.size()); } }