FTPDataSocket.java

/**
 *
 *  Java FTP client library.
 *
 *  Copyright (C) 2000-2003  Enterprise Distributed Technologies Ltd
 *
 *  www.enterprisedt.com
 *
 *  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
 *
 *  Bug fixes, suggestions and comments should be sent to bruce@enterprisedt.com
 *
 *  Change Log:
 *
 *        $Log: FTPDataSocket.java,v $
 *        Revision 1.1.1.1  2005/06/23 15:22:58  smontoro
 *        hipergate backend
 *
 *        Revision 1.1  2004/02/07 03:15:20  hipergate
 *        v2.0 pre-alpha
 *
 *        Revision 1.3  2003/05/31 14:53:44  bruceb
 *        1.2.2 changes
 *
 *        Revision 1.2  2002/11/19 22:01:25  bruceb
 *        changes for 1.2
 *
 *        Revision 1.1  2001/10/09 20:53:46  bruceb
 *        Active mode changes
 *
 *        Revision 1.1  2001/10/05 14:42:03  bruceb
 *        moved from old project
 *
 */

package com.enterprisedt.net.ftp;

import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;

import java.net.Socket;
import java.net.ServerSocket;


/**
 *  Supports client-side FTP DataSocket in Passive and Active Mode.
 *  Wrapper for Socket and ServerSocket. Methods are package access
 *  only - not for public use.
 *
 *  @author      Vladyslav Skarzhevsky
 *  @version     $Revision: 1.1.1.1 $
 */

public class FTPDataSocket {

    /**
     *  Revision control id
     */
    private static String cvsId = "@(#)$Id: FTPDataSocket.java,v 1.1.1.1 2005/06/23 15:22:58 smontoro Exp $";

    /**
     *  The underlying socket for Active connection.
     */
    private ServerSocket activeSocket = null;

    /**
     *  The underlying socket for PASV connection or Socket accepted from server.
     */
    private Socket passiveSocket = null;

    /**
     *  Create socket wrapper for Active connection.
     */
    FTPDataSocket(ServerSocket s) {
         activeSocket = s;
    }

    /**
     *  Create socket wrapper for PASV connection.
     */
    FTPDataSocket(Socket s) {
         passiveSocket = s;
    }


    /**
     *   Set the TCP timeout on the underlying control socket.
     *
     *   If a timeout is set, then any operation which
     *   takes longer than the timeout value will be
     *   killed with a java.io.InterruptedException.
     *
     *   @param millis The length of the timeout, in milliseconds
     */
    void setTimeout(int millis)
        throws IOException {

        if (passiveSocket != null)
            passiveSocket.setSoTimeout(millis);
        else if (activeSocket != null)
            activeSocket.setSoTimeout(millis);
    }


    /**
     *  If active mode, accepts the FTP server's connection - in PASV,
     *  we are already connected. Then gets the output stream of
     *  the connection
     *
     *  @return  output stream for underlying socket.
     */
    OutputStream getOutputStream() throws IOException {

        if (passiveSocket != null) {
            return passiveSocket.getOutputStream();
        }
        else {
            // accept socket from server, in Active mode
            passiveSocket = activeSocket.accept();
            // get and return its OutputStream
            return passiveSocket.getOutputStream ();
        }
    }

    /**
     *  If active mode, accepts the FTP server's connection - in PASV,
     *  we are already connected. Then gets the input stream of
     *  the connection
     *
     *  @return  input stream for underlying socket.
     */
    InputStream getInputStream() throws IOException {

        if (passiveSocket != null) {
            return passiveSocket.getInputStream();
        } else {
            // accept socket from server, in Active mode
            passiveSocket = activeSocket.accept();
            // get and return it's InputStream
            return passiveSocket.getInputStream ();
        }
    }

     /**
      *  Closes underlying sockets.
      */
    void close() throws IOException {

        if (passiveSocket != null)
            passiveSocket.close();
        if (activeSocket != null)
            activeSocket.close();
    }
}