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
015package org.apache.tapestry.services.impl;
016
017import java.io.IOException;
018
019import org.apache.hivemind.ErrorLog;
020import org.apache.hivemind.HiveMind;
021import org.apache.tapestry.services.ResetEventHub;
022import org.apache.tapestry.services.WebRequestServicer;
023import org.apache.tapestry.services.WebRequestServicerFilter;
024import org.apache.tapestry.web.WebRequest;
025import org.apache.tapestry.web.WebResponse;
026
027/**
028 * Filter whose job is to invoke
029 * {@link org.apache.tapestry.services.ResetEventHub#fireResetEvent()}after the request has
030 * been processed. This filter is only contributed into the
031 * tapestry.request.WebRequestServicerPipeline configuration if the
032 * org.apache.tapestry.disable-caching system property is true.
033 * 
034 * @author Howard M. Lewis Ship
035 * @since 4.0
036 */
037public class DisableCachingFilter implements WebRequestServicerFilter
038{
039    private ErrorLog _errorLog;
040
041    private ResetEventHub _resetEventHub;
042
043    public void service(WebRequest request, WebResponse response, WebRequestServicer servicer)
044            throws IOException
045    {
046        try
047        {
048            servicer.service(request, response);
049        }
050        finally
051        {
052            fireResetEvent();
053        }
054
055    }
056
057    private void fireResetEvent()
058    {
059        try
060        {
061            _resetEventHub.fireResetEvent();
062        }
063        catch (Exception ex)
064        {
065            _errorLog.error(ImplMessages.errorResetting(ex), HiveMind.getLocation(ex), ex);
066        }
067    }
068
069    public void setResetEventHub(ResetEventHub resetEventCoordinator)
070    {
071        _resetEventHub = resetEventCoordinator;
072    }
073
074    public void setErrorLog(ErrorLog errorLog)
075    {
076        _errorLog = errorLog;
077    }
078}