001// Copyright 2004, 2005 The Apache Software Foundation 002// 003// Licensed under the Apache License, Version 2.0 (the "License"); 004// you may not use this file except in compliance with the License. 005// You may obtain a copy of the License at 006// 007// http://www.apache.org/licenses/LICENSE-2.0 008// 009// Unless required by applicable law or agreed to in writing, software 010// distributed under the License is distributed on an "AS IS" BASIS, 011// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 012// See the License for the specific language governing permissions and 013// limitations under the License. 014 015package org.apache.hivemind.lib.impl; 016 017import java.rmi.RemoteException; 018 019import org.apache.hivemind.lib.NameLookup; 020import org.apache.hivemind.lib.RemoteExceptionCoordinator; 021 022/** 023 * Generic EJB proxy for stateless session beans. Acts as an InvocationHandler 024 * for a dynamic proxy. 025 * 026 * @author Howard Lewis Ship 027 */ 028public abstract class AbstractEJBProxy 029{ 030 private NameLookup _nameLookup; 031 private RemoteExceptionCoordinator _coordinator; 032 033 protected AbstractEJBProxy(NameLookup nameLookup, RemoteExceptionCoordinator coordinator) 034 { 035 _nameLookup = nameLookup; 036 _coordinator = coordinator; 037 } 038 039 protected Object _lookup(String name) 040 { 041 return _nameLookup.lookup(name, Object.class); 042 } 043 044 /** 045 * Clears the home and remote objects after any remote exception. 046 */ 047 048 protected abstract void _clearCachedReferences(); 049 050 /** 051 * Invoked by the fabricated subclass when a remote exception occurs. 052 * This notifies the {@link RemoteExceptionCoordinator} (which, indirectly, 053 * allows the {@link NameLookup} service to release its JNDI context). 054 * In addition, {@link #_clearCachedReferences()} is invoked. 055 */ 056 protected void _handleRemoteException(RemoteException ex) 057 { 058 _clearCachedReferences(); 059 _coordinator.fireRemoteExceptionDidOccur(this, ex); 060 } 061}