JavaWeb–使用Websocket实现在线聊天功能

package websocket.chat; 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 org.apache.juli.logging.Log; import org.apache.juli.logging.LogFactory; import com.chat.common.HTMLFilter; import com.chat.controller.UserDAOImpl; import com.chat.entity.User; @ServerEndpoint(value = "/index.jsp",configurator=GetHttpSessionConfigurator.class) public class ChatAnnotation { private static final Log log = LogFactory.getLog(ChatAnnotation.class); private static final Map 
    
      connection = new HashMap 
     
       (); private String userId; private String nickname; private Session session; public ChatAnnotation() { } @OnOpen public void start(Session session,EndpointConfig config) { //获取HttpSession对象 HttpSession httpSession = (HttpSession) config.getUserProperties().get(HttpSession.class.getName()); User user = (User)httpSession.getAttribute("user"); String uid = user.getId(); this.nickname = user.getUsername(); this.userId = uid; this.session = session; /*判断链接是否已经在链接队列中，存在就不加*/ if(!connection.containsKey(uid)){ connection.put(uid, this); String message = "* 你已经链接"; toConfirmFriend(message,userId); } } @OnClose public void end() { connection.remove(this.userId); } @OnMessage public void incoming(String message){ String[] all = message.split("-"); //要接收消息好友的ID String uid = all[1]; //判断好友的连接是否存在，不存在就提示好友掉线 if(connection.containsKey(uid)){ String filteredMessage = String.format("%s: %s", nickname, HTMLFilter.filter(all[0].toString())); sendCommonRecord(filteredMessage,uid,this.userId); }else{ ChatAnnotation client = connection.get(uid); String mes = String.format("* %s %s", client.nickname, "已经掉线！"); //将掉线信息发给自己 toConfirmFriend(mes,this.userId); } } @OnError public void onError(Throwable t) throws Throwable { log.error("Chat Error: " + t.toString(), t); } //发送给指定的好友 private static void toConfirmFriend(String msg,String uid) { ChatAnnotation client = connection.get(uid); try { synchronized (client) { client.session.getBasicRemote().sendText(msg); } } catch (IOException e) { log.debug("Chat Error: Failed to send message to "+client.nickname, e); try { client.session.close(); } catch (IOException e1) { // Ignore } } } //给聊天的双发发共同消息 private static void sendCommonRecord(String msg,String sid,String gid) { ChatAnnotation client_send = connection.get(sid); ChatAnnotation client_get = connection.get(gid); try { synchronized (client_send) { client_send.session.getBasicRemote().sendText(msg); } //将这条聊天记录保存在数据库 UserDAOImpl userDAOImpl = new UserDAOImpl(); userDAOImpl.saveCharRecord(msg, sid, gid); } catch (IOException e) { log.debug("Chat Error: Failed to send message to "+client_send.nickname, e); connection.remove(sid); try { client_send.session.close(); }catch (IOException e1) { // Ignore } } try { synchronized (client_get) { client_get.session.getBasicRemote().sendText(msg); } } catch (IOException e) { log.debug("Chat Error: Failed to send message to "+client_get.nickname, e); connection.remove(gid); try { client_get.session.close(); } catch (IOException e1) { // Ignore } } } }