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 edu.emory.mathcs.backport.java.util.concurrent.locks.ReentrantLock; 018 019 import java.io.IOException; 020 021 import org.apache.hivemind.ErrorLog; 022 import org.apache.hivemind.HiveMind; 023 import org.apache.tapestry.services.ResetEventHub; 024 import org.apache.tapestry.services.WebRequestServicer; 025 import org.apache.tapestry.services.WebRequestServicerFilter; 026 import org.apache.tapestry.web.WebRequest; 027 import org.apache.tapestry.web.WebResponse; 028 029 /** 030 * Filter whose job is to invoke 031 * {@link org.apache.tapestry.services.ResetEventHub#fireResetEvent()} after the request has 032 * been processed. This filter is only contributed into the 033 * tapestry.request.WebRequestServicerPipeline configuration if the 034 * org.apache.tapestry.disable-caching system property is true. 035 * 036 * @author Howard M. Lewis Ship 037 * @since 4.0 038 */ 039 public class DisableCachingFilter implements WebRequestServicerFilter 040 { 041 private final ReentrantLock _lock = new ReentrantLock(); 042 043 private ErrorLog _errorLog; 044 045 private ResetEventHub _resetEventHub; 046 047 public void service(WebRequest request, WebResponse response, WebRequestServicer servicer) 048 throws IOException 049 { 050 try 051 { 052 _lock.lock(); 053 054 servicer.service(request, response); 055 } 056 finally 057 { 058 fireResetEvent(); 059 060 _lock.unlock(); 061 } 062 063 } 064 065 private void fireResetEvent() 066 { 067 try 068 { 069 _resetEventHub.fireResetEvent(); 070 } 071 catch (Exception ex) 072 { 073 _errorLog.error(ImplMessages.errorResetting(ex), HiveMind.getLocation(ex), ex); 074 } 075 } 076 077 public void setResetEventHub(ResetEventHub resetEventCoordinator) 078 { 079 _resetEventHub = resetEventCoordinator; 080 } 081 082 public void setErrorLog(ErrorLog errorLog) 083 { 084 _errorLog = errorLog; 085 } 086 }