なぜこの例外が発生するのですか？「デフレータは閉じました」[Websockets]

Question

Facebookのようなチャットアプリケーションを実装しています。

1対1のチャットは、音、通知、メッセージカウンターで完了します。ここで

が、チャット中のある時点で、私はこのエラーでミート

は、私は、なぜ私はこの例外を取得していますことを知らない私のChatSocket.jsクラス

var chatsocket = function() { 

var messageReceive = ""; 

var ws; 

var messageSend = function(message) { 
    var buildMessage = "<div class='row msg_container base_sent'>" 
      + "<div class='col-md-10 col-xs-10'> " 
      + "<div class='messages msg_sent'>" + "<p>" + message + "</p>" 
      + "<time datetime='2009-11-13T20:00'>Timothy • 51 min</time>" 
      + "</div>" + "</div>" + ""; 
    var imgMessage = "<div class='col-md-2 col-xs-2 avatar'>" 
      + "<img src='http://www.bitrebels.com/wp-content/uploads/2011/02/Original-Facebook-Geek-Profile-Avatar-1.jpg'class='img-responsive ' />" 
      + "</div>" + "</div>"; 
    return buildMessage + imgMessage; 
}; 

var messageReceive = function(message) { 
    var imgMessage = "<div class='row msg_container base_receive'>" + 
      "<div class='col-md-2 col-xs-2 avatar'>" 
      + "<img src='http://www.bitrebels.com/wp-content/uploads/2011/02/Original-Facebook-Geek-Profile-Avatar-1.jpg'class='img-responsive ' />" 
      + "</div>"; 

    var buildMessage = "<div class='col-md-10 col-xs-10'> " 
     + "<div class='messages msg_receive'>" + "<p>" + message + "</p>" 
     + "<time datetime='2009-11-13T20:00'>Timothy • 51 min</time>" 
     + "</div>" + "</div>" + "</div>"; 
    return imgMessage + buildMessage; 
}; 

var connect = function() { 
    var user = $("#user").val(); 
    try{ 
     ws = new WebSocket("ws://localhost:8080/EnterpriceChat/chat/" + user); 
    } catch(err) {   
     console.log("error"); 
    } 
    ws.onmessage = function(event) { 
     var message = JSON.parse(event.data); 
     //Refresh the list since there is a user which is online/offline now 
     if(message.content == 'refreshContact') { 
      loadUserContactList(); 
     } else { 
      var idSuffix = getElementIdSuffix(message.from); 
      var status = createNewChatBox(message.from);     
      if(!status) { 
       var msg_panel_id = getMsgPanelId(idSuffix);   
       $("#"+msg_panel_id).append(messageReceive(message.content)); 
      } 
      scrollToBottom(message.from); 
      updateNotification(message.from); 
     } 
    }; 

}; 

var sendMessage = function(element) { 
    var inputElementId = element.attr("data-id"); 
    var to = element.attr("data-id-email"); 
    var msg_panel_id = element.attr("data-id-msg-panel"); 

    //Validating the inputs 
    var content = $("#"+inputElementId).val(); 
    //Reset the input fields 
    $("#"+inputElementId).val(''); 
    if(!content) { 
     return; 
    } 

    var json = JSON.stringify({ 
     "to" : to, 
     "content" : content 
    }); 

    ws.send(json); 
    $("#"+msg_panel_id).append(messageSend(content)); 
}; 

var eventClick = function() { 
    $('.btn-chat-send').unbind('click');   
    $('.chat_input').unbind('keypress'); 
    $('.chat_input').unbind('focus'); 
    $('#userListCategory').find('li').unbind('click'); 
    $('.user_list_entry').unbind('click');  

    $('.btn-chat-send').click(function() { 
     console.log(); 
     sendMessage($(this)); 
     var to = $(this).closest('.input-group').find('.btn-chat-send').attr("data-id-email"); 
     scrollToBottom(to); 
    }); 
    $('.chat_input').keypress(function(e) { 
     if(e.which == 13) { 
      $(this).closest('.input-group').find('.btn-chat-send').click(); 
     } 
    }); 
    $('#userListCategory').find('li').click(function() { 
     var type = $(this).attr("data-id"); 
     $('#userListCategory').attr("data-current-selection", type);    
     loadUserContactList(type); 
    });    
    $('.user_list_entry').click(function() { 
     var selectedUserEmail = $(this).attr('data-id-email'); 
     createNewChatBox(selectedUserEmail); 
     var id = getChatWindowId(getElementIdSuffix(selectedUserEmail)); 
     $('#'+id).find('.chat_input').focus(); 
    }); 
    $('.chat_input').focus(function() {   
     var to = $(this).closest('.input-group').find('.btn-chat-send').attr("data-id-email"); 
     var notificationId = getChatUserNotificationId(getElementIdSuffix(to)); 
     if($('#'+notificationId).text() != '0') { 
      markMessagesAsRead(to); 
     } 
    }); 


}; 

return { 
    initEvent : function() { 
     connect(); 
    }, initAction : function() { 
     eventClick(); 
    }  
} 
}(); 

です例外はnullポインタ例外は、私のコードに私を指していないの

私はその質問は、

1- websocketsのdeflatorの役割は何ですか？また、いくつかの問題に直面している場合は解決方法を教えてください。どのように解決する？

、ここでは私のChatEndPoint.java

package com.chat.config; 

import java.io.IOException; 
import java.util.HashMap; 
import java.util.Set; 
import java.util.TreeSet; 
import java.util.concurrent.CopyOnWriteArraySet; 
import java.util.logging.Logger; 
import javax.websocket.*; 
import javax.websocket.server.PathParam; 
import javax.websocket.server.ServerEndpoint; 

import com.chat.core.dao.ex.SQLException; 
import com.chat.core.repository.MessageRepository; 
import com.chat.core.repository.impl.MessageRepositoryImpl; 
import com.chat.core.util.Constants; 

@ServerEndpoint(value = "/chat/{username}", decoders = MessageDecoder.class, encoders = MessageEncoder.class) 
public class ChatEndPoint { 

private final Logger log = Logger.getLogger(getClass().getName()); 

private static MessageRepository messageRespoitory = MessageRepositoryImpl.getInstance(); 

private Session session; 
private String username; 
private static final Set<ChatEndPoint> chatEndpoints = new CopyOnWriteArraySet<>(); 
private static HashMap<String, String> users = new HashMap<>(); 

@OnOpen 
public void onOpen(Session session, @PathParam("username") String username) throws IOException, EncodeException { 
    log.info(session.getId() + " connected!"); 
    this.session = session; 
    this.username = username; 
    chatEndpoints.add(this); 
    users.put(session.getId(), username); 
    broadcastRefreshContact(); 
    System.out.println("Active endpoints count : " + chatEndpoints.size()); 
    System.out.println("Active endpoints : " + chatEndpoints);  
} 

@OnMessage 
public void onMessage(Session session, Message message) throws IOException, EncodeException { 
    log.info(message.toString()); 
    System.out.println("onMessage : " + message.toString()); 
    message.setFrom(users.get(session.getId())); 
    persistMessage(message); 
    sendMessageToOneUser(message); 
} 

private static void persistMessage(Message message) { 
    try { 
     messageRespoitory.create(message.getFrom(), message.getTo(), message.getContent()); 
    } catch (SQLException e) { 
     System.out.print("Unable to persist message"); 
     e.printStackTrace(); 
    }  
} 

@OnClose 
public void onClose(Session session) throws IOException, EncodeException { 
    log.info(session.getId() + " disconnected!"); 

    chatEndpoints.remove(this); 
    broadcastRefreshContact();  
} 

@OnError 
public void onError(Session session, Throwable throwable) throws IOException, EncodeException { 
    broadcastRefreshContact(); 
    log.warning(throwable.toString()); 
} 

private static void broadcastRefreshContact() throws IOException, EncodeException { 
    Message message = new Message(); 
    message.setContent(Constants.REFRESH_CONTACT); 
    broadcast(message);  
} 

private static void broadcast(Message message) throws IOException, EncodeException { 
    for (ChatEndPoint endpoint : chatEndpoints) { 
     synchronized (endpoint) { 
      endpoint.session.getBasicRemote().sendObject(message); 
     } 
    } 
} 

private static void sendMessageToOneUser(Message message) throws IOException, EncodeException { 
    for (ChatEndPoint endpoint : chatEndpoints) { 
     synchronized (endpoint) { 
      if (endpoint.session.getId().equals(getSessionId(message.getTo()))) { 
       endpoint.session.getBasicRemote().sendObject(message); 
      } 
     } 
    } 
} 

private static String getSessionId(String to) { 
    if (users.containsValue(to)) { 
     for (String sessionId : users.keySet()) { 
      if (users.get(sessionId).equals(to)) { 
       return sessionId; 
      } 
     } 
    } 
    return null; 
} 

public static Set<String> getOnlineUsers() { 
    Set<String> users = new TreeSet<String>(); 
    for(ChatEndPoint enpoint : chatEndpoints) { 
     users.add(enpoint.username); 
    } 
    return users; 
} 

@Override 
public String toString() { 
    return "ChatEndPoint [session=" + session + ", username=" + username 
      + "]"; 
} 

} 

感謝です！

Answer 1

実際にはバックエンドにキャッシュが維持されていたため、その例外の根本原因が見つかりました。ユーザーがリフレッシュしたときに正しく更新されなかったもの。