Source for gnu.classpath.jdwp.transport.JdwpReplyPacket

   1: /* JdwpReplyPacket.java -- JDWP reply packet
   2:    Copyright (C) 2005 Free Software Foundation
   3: 
   4: This file is part of GNU Classpath.
   5: 
   6: GNU Classpath is free software; you can redistribute it and/or modify
   7: it under the terms of the GNU General Public License as published by
   8: the Free Software Foundation; either version 2, or (at your option)
   9: any later version.
  10: 
  11: GNU Classpath is distributed in the hope that it will be useful, but
  12: WITHOUT ANY WARRANTY; without even the implied warranty of
  13: MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14: General Public License for more details.
  15: 
  16: You should have received a copy of the GNU General Public License
  17: along with GNU Classpath; see the file COPYING.  If not, write to the
  18: Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
  19: 02110-1301 USA.
  20: 
  21: Linking this library statically or dynamically with other modules is
  22: making a combined work based on this library.  Thus, the terms and
  23: conditions of the GNU General Public License cover the whole
  24: combination.
  25: 
  26: As a special exception, the copyright holders of this library give you
  27: permission to link this library with independent modules to produce an
  28: executable, regardless of the license terms of these independent
  29: modules, and to copy and distribute the resulting executable under
  30: terms of your choice, provided that you also meet, for each linked
  31: terms of your choice, provided that you also meet, for each linked
  32: independent module, the terms and conditions of the license of that
  33: module.  An independent module is a module which is not derived from
  34: or based on this library.  If you modify this library, you may extend
  35: this exception to your version of the library, but you are not
  36: obligated to do so.  If you do not wish to do so, delete this
  37: exception statement from your version. */
  38: 
  39: 
  40: package gnu.classpath.jdwp.transport;
  41: 
  42: import java.io.DataOutputStream;
  43: import java.io.IOException;
  44: 
  45: /**
  46:  * A class represents a JDWP reply packet.
  47:  * This class adds an error code to the packet header information
  48:  * in {@link gnu.classpath.jdwp.transport.JdwpPacket} and adds additional
  49:  * reply packet-specific processing.
  50:  *
  51:  * @author Keith Seitz  <keiths@redhat.com>
  52:  */
  53: public class JdwpReplyPacket extends JdwpPacket
  54: {
  55:   /**
  56:    * Error code
  57:    */
  58:   protected short _errorCode;
  59: 
  60:   // Minimum packet size [excluding super class] ( errorCode (2) )
  61:   private static final int MINIMUM_LENGTH = 2;
  62: 
  63:   /**
  64:    * Constructs a <code>JdwpReplyPacket</code>.
  65:    */
  66:   public JdwpReplyPacket ()
  67:   {
  68:     // Don't assign a packet id. This is called by JdwpPacket.fromBytes
  69:     // which assigns a packet id. (Not that a VM would do that...)
  70:   }
  71: 
  72:   /**
  73:    * Constructs a <code>JdwpReplyPacket</code> with the
  74:    * id from the given packet and error code
  75:    *
  76:    * @param pkt        the packet whose id this packet will use
  77:    * @param errorCode  the error code
  78:    */
  79:   public JdwpReplyPacket (JdwpPacket pkt, short errorCode)
  80:   {
  81:     this(pkt);
  82:     _errorCode = errorCode;
  83:   }
  84: 
  85:   /**
  86:    * Constructs a <code>JdwpReplyPacket</code> with the
  87:    * id from the given packet and an empty error code
  88:    *
  89:    * @param pkt        the packet whose id this packet will use
  90:    */
  91:   public JdwpReplyPacket (JdwpPacket pkt)
  92:   {
  93:     super (pkt);
  94:     _flags = (byte) JDWP_FLAG_REPLY;
  95:   }
  96: 
  97:   /**
  98:    * Returns the length of this packet
  99:    */
 100:   public int getLength ()
 101:   {
 102:     return MINIMUM_LENGTH + super.getLength ();
 103:   }
 104: 
 105:   /**
 106:    * Returns the error code
 107:    */
 108:   public short getErrorCode ()
 109:   {
 110:     return _errorCode;
 111:   }
 112: 
 113:   /**
 114:    * Sets the error code
 115:    */
 116:   public void setErrorCode (short ec)
 117:   {
 118:     _errorCode = ec;
 119:   }
 120: 
 121:   // Reads command packet data from the given buffer, starting
 122:   // at the given offset
 123:   protected int myFromBytes (byte[] bytes, int index)
 124:   {
 125:     int i = 0;
 126:     setErrorCode ((short) ((bytes[index + i++] & 0xff) << 8
 127:                            | (bytes[index + i++] & 0xff)));
 128:     return i;
 129:   }
 130: 
 131:   // Writes the command packet data into the given buffer
 132:   protected void myWrite (DataOutputStream dos)
 133:     throws IOException
 134:  {
 135:     dos.writeShort (getErrorCode ());
 136:   }
 137: }