UPMT-master/java/upmt/src/org/zoolu/net/TcpConnection.java
/*
 * Copyright (C) 2005 Luca Veltri - University of Parma - Italy
 * 
 * This file is part of MjSip (http://www.mjsip.org)
 * 
 * MjSip is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 * 
 * MjSip 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 General Public License for more details.
 * 
 * You should have received a copy of the GNU General Public License
 * along with MjSip; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 * 
 * Author(s):
 * Luca Veltri (luca.veltri@unipr.it)
 */

package org.zoolu.net;


//import java.net.InetAddress;
import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.InterruptedIOException;
import java.io.OutputStream;


/** TcpConnection provides a TCP connection oriented transport service.
  */
public class TcpConnection extends Thread
{
   /** The reading buffer size */
   static final int BUFFER_SIZE=65535;

   /** Default value for the maximum time that the tcp connection can remain active after been halted (in milliseconds) */
   public static final int DEFAULT_SOCKET_TIMEOUT=2000; // 2sec 

   /** The TCP socket */ 
   TcpSocket socket;  

   /** Maximum time that the connection can remain active after been halted (in milliseconds) */
   int socket_timeout;

   /** Maximum time that the connection remains active without receiving data (in milliseconds) */
   long alive_time; 

   /** The InputStream */
   InputStream istream;
   
   /** The OutputStream */
   OutputStream ostream;

   /** InputStream/OutputStream error */
   Exception error;

   /** Whether it has been halted */
   boolean stop; 

   /** Whether it is running */
   boolean is_running; 

   /** TcpConnection listener */
   TcpConnectionListener listener;


   /** Costructs a new TcpConnection */
   public TcpConnection(TcpSocket socket, TcpConnectionListener listener)
   {  init(socket,0,listener);
      start();
   }


   /** Costructs a new TcpConnection */
   public TcpConnection(TcpSocket socket, long alive_time, TcpConnectionListener listener)
   {  init(socket,alive_time,listener);
      start();
   }


   /** Inits the TcpConnection */
   private void init(TcpSocket socket, long alive_time, TcpConnectionListener listener)
   {  this.listener=listener;
      this.socket=socket;
      this.socket_timeout=DEFAULT_SOCKET_TIMEOUT;
      this.alive_time=alive_time;
      this.stop=false; 
      this.is_running=true; 

      this.istream=null;
      this.ostream=null;
      this.error=null;
      try
      {  istream=new BufferedInputStream(socket.getInputStream());
         ostream=new BufferedOutputStream(socket.getOutputStream());
      }
      catch (Exception e)
      {  error=e;
      }
   }


   /** Whether the service is running */
   public boolean isRunning()
   {  return is_running;
   }


   /** Gets the TcpSocket */ 
   public TcpSocket getSocket()
   {  return socket;
   }


   /** Gets the remote IP address */
   public IpAddress getRemoteAddress()
   {  return socket.getAddress();
   }

   
   /** Gets the remote port */
   public int getRemotePort()
   {  return socket.getPort();
   }

  
   /** Stops running */
   public void halt()
   {  stop=true;
   }


   /** Sends data */
   public void send(byte[] buff, int offset, int len)  throws IOException
   {  if (!stop && ostream!=null)
      {  ostream.write(buff,offset,len);
         ostream.flush();
      }
   }


   /** Sends data */
   public void send(byte[] buff)  throws IOException
   {  send(buff,0,buff.length);
   }


   /** Runs the tcp receiver */
   public void run()
   {
      byte[] buff=new byte[BUFFER_SIZE];
      long expire=0;
      if (alive_time>0) expire=System.currentTimeMillis()+alive_time;
      try
      {  if (error!=null) throw error;
         socket.setSoTimeout(socket_timeout);         
         // loop
         while(!stop)
         {  int len=0;
            if (istream!=null)
            {  try
               {  len=istream.read(buff);
               }
               catch (InterruptedIOException ie)
               {  if (alive_time>0 && System.currentTimeMillis()>expire) halt();
                  continue;
               }
            }
            if (len<0)
            {  //error=new Exception("TCP connection closed");
               stop=true;
            }
            else
            if (len>0)
            {  if (listener!=null) listener.onReceivedData(this,buff,len);
               if (alive_time>0) expire=System.currentTimeMillis()+alive_time;
            }
         }
      }
      catch (Exception e)
      {  error=e;
         stop=true;
      }
      is_running=false;
      if (istream!=null) try {  istream.close();  } catch (Exception e) {}
      if (ostream!=null) try {  ostream.close();  } catch (Exception e) {}
      if (listener!=null) listener.onConnectionTerminated(this,error);
      listener=null;
   } 

 
   /** Gets a String representation of the Object */
   public String toString()
   {  return "tcp:"+socket.getLocalAddress()+":"+socket.getLocalPort()+"<->"+socket.getAddress()+":"+socket.getPort();
   }

}
