1 /* RemoteObject.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 package java.rmi.server;
39
40 import java.io.IOException;
41 import java.io.ObjectInputStream;
42 import java.io.ObjectOutputStream;
43 import java.io.Serializable;
44 import java.rmi.NoSuchObjectException;
45 import java.rmi.Remote;
46 import java.rmi.UnmarshalException;
47 import java.util.WeakHashMap;
48
49 public abstract class RemoteObject
50 implements Remote, Serializable {
51
52 private static final long serialVersionUID = -3215090123894869218l;
53
54 protected transient RemoteRef ref;
55
56 private static final WeakHashMap stubs = new WeakHashMap();
57
RemoteObject()58 protected RemoteObject() {
59 this(null);
60 }
61
RemoteObject(RemoteRef newref)62 protected RemoteObject(RemoteRef newref) {
63 ref = newref;
64 }
65
getRef()66 public RemoteRef getRef() {
67 return (ref);
68 }
69
addStub(Remote obj, Remote stub)70 synchronized static void addStub(Remote obj, Remote stub)
71 {
72 stubs.put(obj, stub);
73 }
74
deleteStub(Remote obj)75 synchronized static void deleteStub(Remote obj)
76 {
77 stubs.remove(obj);
78 }
79
toStub(Remote obj)80 public static Remote toStub(Remote obj) throws NoSuchObjectException
81 {
82 Remote stub = (Remote)stubs.get(obj);
83
84 if (stub == null)
85 throw new NoSuchObjectException(obj.getClass().getName());
86
87 return stub;
88 }
89
hashCode()90 public int hashCode() {
91 if (ref == null) {
92 return (0);
93 }
94 else {
95 return (ref.hashCode());
96 }
97 }
98
equals(Object obj)99 public boolean equals(Object obj) {
100 // We only compare references.
101 return (this == obj);
102 }
103
toString()104 public String toString()
105 {
106 if (ref == null)
107 return getClass ().toString ();
108 return (ref.toString ());
109 }
110
readObject(ObjectInputStream in)111 private void readObject(ObjectInputStream in) throws IOException, ClassNotFoundException
112 {
113 String cname = in.readUTF();
114 if (!cname.equals(""))
115 {
116 if (cname.equals ("UnicastRef2"))
117 {
118 // hack for interoperating with JDK
119 cname = "UnicastRef";
120 in.read (); //some unknown UnicastRef2 field
121 }
122
123 // It would be nice to use RemoteRef.packagePrefix here, but for binary
124 // compatibility with the JDK that has to contain "sun.rmi.server"...
125 cname = "gnu.java.rmi.server." + cname;
126 try
127 {
128 Class cls = Class.forName(cname);
129 ref = (RemoteRef)cls.newInstance();
130 }
131 catch (InstantiationException e1)
132 {
133 throw new UnmarshalException("failed to create ref", e1);
134 }
135 catch (IllegalAccessException e2)
136 {
137 throw new UnmarshalException("failed to create ref", e2);
138 }
139 ref.readExternal(in);
140 }
141 else
142 {
143 ref = (RemoteRef)in.readObject();
144 }
145 }
146
writeObject(ObjectOutputStream out)147 private void writeObject(ObjectOutputStream out) throws IOException, ClassNotFoundException {
148 if (ref == null) {
149 throw new UnmarshalException("no ref to serialize");
150 }
151 String cname = ref.getRefClass(out);
152 if (cname != null && cname.length() > 0) {
153 out.writeUTF(cname);
154 ref.writeExternal(out);
155 }
156 else {
157 out.writeUTF("");
158 out.writeObject(ref);
159 }
160 }
161
162 }
163