001 // Copyright 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. 014 015 package org.apache.tapestry.services.impl; 016 017 import java.io.IOException; 018 019 import org.apache.hivemind.util.Defense; 020 import org.apache.tapestry.IRequestCycle; 021 import org.apache.tapestry.engine.IEngineService; 022 import org.apache.tapestry.engine.ILink; 023 024 /** 025 * Inner proxy that actually resolves the engine service using the 026 * {@link org.apache.tapestry.services.impl.EngineServiceSource}, then replaces itself in the outer 027 * proxy. 028 * 029 * @author Howard M. Lewis Ship 030 * @since 4.0 031 * @see org.apache.tapestry.services.impl.EngineServiceOuterProxy 032 */ 033 public class EngineServiceInnerProxy implements IEngineService 034 { 035 private final String _serviceName; 036 037 private final EngineServiceOuterProxy _outerProxy; 038 039 private final EngineServiceSource _source; 040 041 public EngineServiceInnerProxy(String serviceName, EngineServiceOuterProxy outerProxy, 042 EngineServiceSource source) 043 { 044 Defense.notNull(serviceName, "serviceName"); 045 Defense.notNull(outerProxy, "outerProxy"); 046 Defense.notNull(source, "source"); 047 048 _serviceName = serviceName; 049 _outerProxy = outerProxy; 050 _source = source; 051 } 052 053 public String toString() 054 { 055 return ImplMessages.engineServiceInnerProxyToString(_serviceName); 056 } 057 058 private IEngineService resolve() 059 { 060 IEngineService service = _source.resolveEngineService(_serviceName); 061 062 _outerProxy.installDelegate(service); 063 064 return service; 065 } 066 067 public synchronized ILink getLink(IRequestCycle cycle, boolean post, Object parameter) 068 { 069 return resolve().getLink(cycle, false, parameter); 070 } 071 072 public synchronized void service(IRequestCycle cycle) throws IOException 073 { 074 resolve().service(cycle); 075 } 076 077 public String getName() 078 { 079 return _serviceName; 080 } 081 082 }