websocket实现即时通信

package com.socket; import java.io.IOException; import java.util.HashMap; import java.util.Map; import javax.servlet.http.HttpSession; import javax.websocket.EndpointConfig; import javax.websocket.OnClose; import javax.websocket.OnError; import javax.websocket.OnMessage; import javax.websocket.OnOpen; import javax.websocket.Session; import javax.websocket.server.ServerEndpoint; import utils.MessageUtil; @ServerEndpoint(value = "/websocket",configurator=GetHttpSessionConfigurator.class) public class ChatServlet { private static final Map<HttpSession,ChatServlet> onlineUsers = new HashMap<HttpSession, ChatServlet>(); private static int onlineCount = 0;//上线人数 private HttpSession httpSession; private Session session; @OnOpen public void onOpen(Session session,EndpointConfig config){ this.session = session; this.httpSession = (HttpSession) config.getUserProperties().get(HttpSession.class.getName()); if(httpSession.getAttribute("user") != null){ onlineUsers.put(httpSession, this); } String names = getNames(); String content = MessageUtil.sendContent(MessageUtil.USER,names); broadcastAll(content); addOnlineCount(); //在线数加1 System.out.println("有新连接加入!当前在线人数为" + onlineUsers.size()); } @OnClose public void onClose(){ onlineUsers.remove(this); //从set中删除 subOnlineCount(); //在线数减1 System.out.println("有一连接关闭！当前在线人数为" + getOnlineCount()); } @OnMessage public void onMessage(String message, Session session) throws IOException { HashMap<String,String> messageMap = MessageUtil.getMessage(message); //处理消息类 String fromName = messageMap.get("fromName"); //消息来自人 的userId String toName = messageMap.get("toName"); //消息发往人的 userId String mapContent = messageMap.get("content"); String time = messageMap.get("time"); if(toName.isEmpty()){ sendOffLine(fromName,toName); return; } //"|"是分隔符，用于前台处理 String msgContentString = fromName + "|" + mapContent+"|"+time; //构造发送的消息 if("all".equals(toName)){ String content = MessageUtil.sendContent(MessageUtil.MESSAGE,msgContentString); broadcastAll(content); }else{ try { String content = MessageUtil.sendContent(MessageUtil.MESSAGE,msgContentString); singleChat(fromName,toName,content); } catch (IOException e) { e.printStackTrace(); } } System.out.println("来自客户端的消息:" + message); broadcastAll(message); } private void singleChat(String fromName, String toName, String mapContent) throws IOException { boolean isExit = false; for (HttpSession key : onlineUsers.keySet()) { if(key.getAttribute("user").equals(toName)){ isExit = true; } } if(isExit){ for (HttpSession key : onlineUsers.keySet()) { if(key.getAttribute("user").equals(fromName) || key.getAttribute("user").equals(toName)){ onlineUsers.get(key).session.getBasicRemote().sendText(mapContent); } } }else{ String content = MessageUtil.sendContent(MessageUtil.MESSAGE,"客服不在线请留言..."); broadcastAll(content); } } private void sendOffLine(String fromName, String toName) throws IOException { String msgContentString = toName + "不在线"; String content = MessageUtil.sendContent(MessageUtil.MESSAGE,msgContentString); for (HttpSession key : onlineUsers.keySet()) { if(key.getAttribute("user").equals(fromName) || key.getAttribute("user").equals(toName)){ onlineUsers.get(key).session.getBasicRemote().sendText(content); } } } private static void broadcastAll(String msg) { System.out.println(msg); for (HttpSession key : onlineUsers.keySet()) { try { onlineUsers.get(key).session.getBasicRemote().sendText(msg); } catch (IOException e) { e.printStackTrace(); } } } @OnError public void onError(Session session, Throwable error){ System.out.println("发生错误"); error.printStackTrace(); } private String getNames() { String names = ""; for (HttpSession key : onlineUsers.keySet()) { String name = (String) key.getAttribute("user"); names += name + ","; } String namesTemp = names.substring(0,names.length()-1); return namesTemp; } public static synchronized int getOnlineCount() { return onlineCount; } public static synchronized void addOnlineCount() { ChatServlet.onlineCount++; } public static synchronized void subOnlineCount() { ChatServlet.onlineCount--; } }