Source for java.rmi.MarshalledObject

   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., 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: 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: }