001/* RemoteRef.java -- 002 Copyright (c) 1996, 1997, 1998, 1999, 2004, 2006 003 Free Software Foundation, Inc. 004 005This file is part of GNU Classpath. 006 007GNU Classpath is free software; you can redistribute it and/or modify 008it under the terms of the GNU General Public License as published by 009the Free Software Foundation; either version 2, or (at your option) 010any later version. 011 012GNU Classpath is distributed in the hope that it will be useful, but 013WITHOUT ANY WARRANTY; without even the implied warranty of 014MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 015General Public License for more details. 016 017You should have received a copy of the GNU General Public License 018along with GNU Classpath; see the file COPYING. If not, write to the 019Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02002110-1301 USA. 021 022Linking this library statically or dynamically with other modules is 023making a combined work based on this library. Thus, the terms and 024conditions of the GNU General Public License cover the whole 025combination. 026 027As a special exception, the copyright holders of this library give you 028permission to link this library with independent modules to produce an 029executable, regardless of the license terms of these independent 030modules, and to copy and distribute the resulting executable under 031terms of your choice, provided that you also meet, for each linked 032independent module, the terms and conditions of the license of that 033module. An independent module is a module which is not derived from 034or based on this library. If you modify this library, you may extend 035this exception to your version of the library, but you are not 036obligated to do so. If you do not wish to do so, delete this 037exception statement from your version. */ 038 039 040package java.rmi.server; 041 042import java.io.Externalizable; 043import java.io.ObjectOutput; 044import java.lang.reflect.Method; 045import java.rmi.Remote; 046import 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 */ 053public 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}