messagefactory.java

P2P协议GUNTELLA的java源代码

/*
 * Copyright (C) 2000-2001  Ken McCrary
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *
 * Email: [e-mail]
 */
package com.kenmccrary.jtella;

import com.kenmccrary.jtella.util.Log;

/**
 *  Construct the appropriate <code>Message</code>
 *  subclass
 *
 */
class MessageFactory
{
  /**
   *  Location of the function type in the header
   *
   */
  final static int typeLocation = 16;

  /**
   *  Factory method providing messages
   *
   */
  static Message createMessage(short[] rawMessage, Connection originatingConnection)
  {
    short type = rawMessage[typeLocation];
    Message message = null;

    switch ( type ) 
    {
      case Message.PING:
      {
        Log.getLog().logInformation("MessageFactory created a ping message");
        message = new PingMessage(rawMessage, originatingConnection);
        break;
      }

      case Message.PONG:
      {
        Log.getLog().logInformation("MessageFactory created a pong message");
        message = new PongMessage(rawMessage, originatingConnection);
        break;
      }

      case Message.QUERY:
      {
        Log.getLog().logInformation("MessageFactory created a query message");
        message = new SearchMessage(rawMessage, originatingConnection);
        break;
      } 

      case Message.QUERYREPLY:
      {
        Log.getLog().logInformation("MessageFactory created a query reply message");
        message = new SearchReplyMessage(rawMessage, originatingConnection);
        break;
      }

      case Message.PUSH:
      {
        Log.getLog().logInformation("MessageFactory created a push message");
        message = new PushMessage(rawMessage, originatingConnection);
        break;
      }

      default:
      {
        Log.getLog().logError("Message factory can't create message, type: " + type);
        Log.getLog().logError("Message factory can't create message, raw bytes: \n");

        StringBuffer buffer = new StringBuffer();
        for (int i = 0; i < rawMessage.length; i++) 
        {
          buffer.append("[" +
                        Integer.toHexString(rawMessage[i]) +
                        "]");
   
        }
        Log.getLog().logError(buffer.toString());
        break;
      }
    }

    return message;
  }
}