libjava/java/rmi/MarshalledObject.java

   1 /* MarshalledObject.java --
   2    Copyright (c) 1996, 1997, 1998, 1999, 2004 Free Software Foundation, Inc.
   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., 59 Temple Place, Suite 330, Boston, MA
  19 02111-1307 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 independent module, the terms and conditions of the license of that
  32 module.  An independent module is a module which is not derived from
  33 or based on this library.  If you modify this library, you may extend
  34 this exception to your version of the library, but you are not
  35 obligated to do so.  If you do not wish to do so, delete this
  36 exception statement from your version. */
  37
  38
  39 package java.rmi;
  40
  41 import gnu.java.rmi.RMIMarshalledObjectInputStream;
  42 import gnu.java.rmi.RMIMarshalledObjectOutputStream;
  43
  44 import java.io.ByteArrayOutputStream;
  45 import java.io.Serializable;
  46
  47 /**
  48  * FIXME - doc missing
  49  */
  50 public final class MarshalledObject implements Serializable
  51 {
  52   //The following fields are from Java API Documentation "Serialized form"
  53   private static final long serialVersionUID = 8988374069173025854L;
  54   byte[] objBytes;
  55   byte[] locBytes;
  56   int hash;
  57
  58   public MarshalledObject(Object obj) throws java.io.IOException
  59   {
  60     ByteArrayOutputStream objStream = new ByteArrayOutputStream();
  61     RMIMarshalledObjectOutputStream stream = new RMIMarshalledObjectOutputStream(objStream);
  62     stream.writeObject(obj);
  63     stream.flush();
  64     objBytes = objStream.toByteArray();
  65     locBytes = stream.getLocBytes();
  66
  67     //The following algorithm of calculating hashCode is similar to String
  68     hash = 0;
  69     for (int i = 0; i < objBytes.length; i++)
  70       hash = hash * 31 + objBytes[i];
  71     if(locBytes != null)
  72       for (int i = 0; i < locBytes.length; i++)
  73         hash = hash * 31 + locBytes[i];
  74   }
  75
  76   public boolean equals(Object obj)
  77   {
  78     if (! (obj instanceof MarshalledObject))
  79       return false;
  80
  81     // hashCode even differs, don't do the time-consuming comparisons
  82     if (obj.hashCode() != hash)
  83       return false;
  84
  85     MarshalledObject aobj = (MarshalledObject)obj;
  86     if (objBytes == null || aobj.objBytes == null)
  87       return objBytes == aobj.objBytes;
  88     if (objBytes.length != aobj.objBytes.length)
  89       return false;
  90     for (int i = 0; i < objBytes.length; i++)
  91       {
  92         if (objBytes[i] != aobj.objBytes[i])
  93           return false;
  94       }
  95     // Ignore comparison of locBytes(annotation)
  96     return true;
  97   }
  98
  99 public Object get()
 100   throws java.io.IOException, java.lang.ClassNotFoundException
 101 {
 102   if(objBytes == null)
 103     return null;
 104   RMIMarshalledObjectInputStream stream =
 105     new RMIMarshalledObjectInputStream(objBytes, locBytes);
 106   return stream.readObject();
 107 }
 108
 109   public int hashCode() {
 110     return hash;
 111   }
 112
 113 }