001/* 002 * Copyright 2002-2012 the original author or authors. 003 * 004 * Licensed under the Apache License, Version 2.0 (the "License"); 005 * you may not use this file except in compliance with the License. 006 * You may obtain a copy of the License at 007 * 008 * https://www.apache.org/licenses/LICENSE-2.0 009 * 010 * Unless required by applicable law or agreed to in writing, software 011 * distributed under the License is distributed on an "AS IS" BASIS, 012 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 013 * See the License for the specific language governing permissions and 014 * limitations under the License. 015 */ 016 017package org.springframework.remoting.rmi; 018 019import java.lang.reflect.InvocationTargetException; 020import java.rmi.Remote; 021 022import org.springframework.remoting.support.RemoteInvocation; 023import org.springframework.remoting.support.RemoteInvocationBasedExporter; 024 025/** 026 * Convenient superclass for RMI-based remote exporters. Provides a facility 027 * to automatically wrap a given plain Java service object with an 028 * RmiInvocationWrapper, exposing the {@link RmiInvocationHandler} remote interface. 029 * 030 * <p>Using the RMI invoker mechanism, RMI communication operates at the {@link RmiInvocationHandler} 031 * level, sharing a common invoker stub for any number of services. Service interfaces are <i>not</i> 032 * required to extend {@code java.rmi.Remote} or declare {@code java.rmi.RemoteException} 033 * on all service methods. However, in and out parameters still have to be serializable. 034 * 035 * @author Juergen Hoeller 036 * @since 1.2.5 037 * @see RmiServiceExporter 038 * @see JndiRmiServiceExporter 039 */ 040public abstract class RmiBasedExporter extends RemoteInvocationBasedExporter { 041 042 /** 043 * Determine the object to export: either the service object itself 044 * or a RmiInvocationWrapper in case of a non-RMI service object. 045 * @return the RMI object to export 046 * @see #setService 047 * @see #setServiceInterface 048 */ 049 protected Remote getObjectToExport() { 050 // determine remote object 051 if (getService() instanceof Remote && 052 (getServiceInterface() == null || Remote.class.isAssignableFrom(getServiceInterface()))) { 053 // conventional RMI service 054 return (Remote) getService(); 055 } 056 else { 057 // RMI invoker 058 if (logger.isDebugEnabled()) { 059 logger.debug("RMI service [" + getService() + "] is an RMI invoker"); 060 } 061 return new RmiInvocationWrapper(getProxyForService(), this); 062 } 063 } 064 065 /** 066 * Redefined here to be visible to RmiInvocationWrapper. 067 * Simply delegates to the corresponding superclass method. 068 */ 069 @Override 070 protected Object invoke(RemoteInvocation invocation, Object targetObject) 071 throws NoSuchMethodException, IllegalAccessException, InvocationTargetException { 072 073 return super.invoke(invocation, targetObject); 074 } 075 076}