001 /* RemoteRef.java --
002 Copyright (c) 1996, 1997, 1998, 1999, 2004, 2006
003 Free Software Foundation, Inc.
004
005 This file is part of GNU Classpath.
006
007 GNU Classpath is free software; you can redistribute it and/or modify
008 it under the terms of the GNU General Public License as published by
009 the Free Software Foundation; either version 2, or (at your option)
010 any later version.
011
012 GNU Classpath is distributed in the hope that it will be useful, but
013 WITHOUT ANY WARRANTY; without even the implied warranty of
014 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
015 General Public License for more details.
016
017 You should have received a copy of the GNU General Public License
018 along with GNU Classpath; see the file COPYING. If not, write to the
019 Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
020 02110-1301 USA.
021
022 Linking this library statically or dynamically with other modules is
023 making a combined work based on this library. Thus, the terms and
024 conditions of the GNU General Public License cover the whole
025 combination.
026
027 As a special exception, the copyright holders of this library give you
028 permission to link this library with independent modules to produce an
029 executable, regardless of the license terms of these independent
030 modules, and to copy and distribute the resulting executable under
031 terms of your choice, provided that you also meet, for each linked
032 independent module, the terms and conditions of the license of that
033 module. An independent module is a module which is not derived from
034 or based on this library. If you modify this library, you may extend
035 this exception to your version of the library, but you are not
036 obligated to do so. If you do not wish to do so, delete this
037 exception statement from your version. */
038
039
040 package java.rmi.server;
041
042 import java.io.Externalizable;
043 import java.io.ObjectOutput;
044 import java.lang.reflect.Method;
045 import java.rmi.Remote;
046 import java.rmi.RemoteException;
047
048 /**
049 * Represents a handler to the remote object. Each instance of the
050 * {@link RemoteStub} contains such handler and uses it to invoke remote
051 * methods via {@link #invoke(Remote, Method, Object[], long)}.
052 */
053 public interface RemoteRef extends Externalizable
054 {
055 /**
056 * Indicates compatibility with JDK 1.1.*
057 */
058 long serialVersionUID = 3632638527362204081L;
059
060 /**
061 * For binary compatibility with the JDK, the string "sun.rmi.server".
062 * Not actually used for anything.
063 */
064 String packagePrefix = "sun.rmi.server";
065
066 /**
067 * @deprecated use {@link #invoke(Remote, Method, Object[], long)} instead.
068 */
069 void invoke (RemoteCall call) throws Exception;
070
071 /**
072 * Invoke a method. This method either returns the result of remote invocation
073 * or throws RemoteException if the remote call failed. Other exceptions may
074 * be thrown if some problem has occured in the application level.
075 *
076 * @param obj the object, containing the remote reference (for instance,
077 * remote stub, generated by rmic).
078 * @param method the method to invoke
079 * @param params the method parameters
080 * @param methodHash a persistent hash code that can be used to represent a
081 * method
082 * @return the result of the remote invocation
083 * @throws RemoteException if the remote call has failed
084 * @throws Exception if one is raised at the application level
085 */
086 Object invoke (Remote obj, Method method, Object[] params, long methodHash)
087 throws Exception;
088
089 /**
090 * @deprecated use {@link #invoke(Remote, Method, Object[], long)} instead.
091 */
092 RemoteCall newCall (RemoteObject obj, Operation[] op, int opnum, long hash)
093 throws RemoteException;
094
095 /**
096 * @deprecated use {@link #invoke(Remote, Method, Object[], long)} instead.
097 */
098 void done (RemoteCall call) throws RemoteException;
099
100 /**
101 * Compare two remote objects for equality. The references are equal if
102 * they point to the same remote object.
103 *
104 * @param ref the reference to compare.
105 *
106 * @return true if this and passed references both point to the same remote
107 * object, false otherwise.
108 */
109 boolean remoteEquals (RemoteRef ref);
110
111 /**
112 * Get the hashcode for a remote object. Two remote object stubs, referring
113 * to the same remote object, have the same hash code.
114 *
115 * @return the hashcode of the remote object
116 */
117 int remoteHashCode();
118
119
120 /**
121 * Returns the class name of the reference type that must be written to the
122 * given stream. When writing, this returned name is passed first, and
123 * the reference.writeExternal(out) writes the reference specific data.
124 *
125 * @param out the stream, where the data must be written
126 *
127 * @return the class name.
128 */
129 String getRefClass (ObjectOutput out);
130
131 /**
132 * Get the string representation of this remote reference.
133 *
134 * @return the string representation.
135 */
136 String remoteToString();
137 }