libjava/java/rmi/server/RemoteObject.java

   1 /*
   2   Copyright (c) 1996, 1997, 1998, 1999 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 package java.rmi.server;
  39
  40 import java.io.Serializable;
  41 import java.rmi.Remote;
  42 import java.rmi.NoSuchObjectException;
  43 import java.rmi.UnmarshalException;
  44 import java.rmi.server.RemoteRef;
  45 import java.io.ObjectInputStream;
  46 import java.io.ObjectOutputStream;
  47 import java.io.IOException;
  48 import java.lang.ClassNotFoundException;
  49 import java.lang.InstantiationException;
  50 import java.lang.IllegalAccessException;
  51 import java.lang.reflect.Constructor;
  52
  53 public abstract class RemoteObject
  54         implements Remote, Serializable {
  55
  56 public static final long serialVersionUID = -3215090123894869218l;
  57
  58 protected transient RemoteRef ref;
  59
  60 protected RemoteObject() {
  61         this(null);
  62 }
  63
  64 protected RemoteObject(RemoteRef newref) {
  65         ref = newref;
  66 }
  67
  68 public RemoteRef getRef() {
  69         return (ref);
  70 }
  71
  72   public static Remote toStub(Remote obj) throws NoSuchObjectException
  73   {
  74     Class cls = obj.getClass();
  75     String classname = cls.getName();
  76     ClassLoader cl = cls.getClassLoader();
  77     try
  78       {
  79         Class scls = cl.loadClass(classname + "_Stub");
  80         // JDK 1.2 stubs
  81         Class[] stubprototype = new Class[] { RemoteRef.class };
  82         Constructor con = scls.getConstructor(stubprototype);
  83         return (Remote)(con.newInstance(new Object[]{obj}));
  84       }
  85     catch (Exception e) {}
  86     throw new NoSuchObjectException(obj.getClass().getName());
  87   }
  88
  89 public int hashCode() {
  90         if (ref == null) {
  91                 return (0);
  92         }
  93         else {
  94                 return (ref.hashCode());
  95         }
  96 }
  97
  98 public boolean equals(Object obj) {
  99         // We only compare references.
 100         return (this == obj);
 101 }
 102
 103   public String toString()
 104   {
 105     if (ref == null)
 106       return getClass ().toString ();
 107     return (ref.toString ());
 108   }
 109
 110   private void readObject(ObjectInputStream in) throws IOException, ClassNotFoundException
 111   {
 112     String cname = in.readUTF();
 113     if (!cname.equals(""))
 114       {
 115         if (cname.equals ("UnicastRef2"))
 116           {
 117             // hack for interoperating with JDK
 118             cname = "UnicastRef";
 119             in.read (); //some unknown UnicastRef2 field
 120           }
 121
 122         cname = RemoteRef.packagePrefix + '.' + cname;
 123         try
 124           {
 125             Class cls = Class.forName(cname);
 126             ref = (RemoteRef)cls.newInstance();
 127           }
 128         catch (InstantiationException e1)
 129           {
 130             throw new UnmarshalException("failed to create ref", e1);
 131           }
 132         catch (IllegalAccessException e2)
 133           {
 134             throw new UnmarshalException("failed to create ref", e2);
 135           }
 136         ref.readExternal(in);
 137       }
 138     else
 139       {
 140         ref = (RemoteRef)in.readObject();
 141       }
 142   }
 143
 144 private void writeObject(ObjectOutputStream out) throws IOException, ClassNotFoundException {
 145         if (ref == null) {
 146                 throw new UnmarshalException("no ref to serialize");
 147         }
 148         String cname = ref.getRefClass(out);
 149         if (cname != null && cname.length() > 0) {
 150                 out.writeUTF(cname);
 151                 ref.writeExternal(out);
 152         }
 153         else {
 154                 out.writeUTF("");
 155                 out.writeObject(ref);
 156         }
 157 }
 158
 159 }