001// Copyright 2010, 2013 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.tapestry5.internal.services.assets;
016
017import org.apache.tapestry5.commons.Resource;
018import org.apache.tapestry5.http.services.Request;
019import org.apache.tapestry5.http.services.Response;
020import org.apache.tapestry5.internal.services.ResourceStreamer;
021import org.apache.tapestry5.services.AssetSource;
022import org.apache.tapestry5.services.ClasspathAssetAliasManager;
023import org.apache.tapestry5.services.ClasspathAssetProtectionRule;
024import org.apache.tapestry5.services.assets.AssetRequestHandler;
025
026import java.io.IOException;
027
028/**
029 * A handler for asset requests for classpath assets (within a specific folder).
030 * Each mapping of the {@link ClasspathAssetAliasManager} gets one of these.
031 *
032 * @since 5.2.0
033 */
034public class ClasspathAssetRequestHandler implements AssetRequestHandler
035{
036    private final ResourceStreamer streamer;
037
038    private final AssetSource assetSource;
039    
040    private final String baseFolder;
041    
042    private final ClasspathAssetProtectionRule classpathAssetProtectionRule;
043
044    public ClasspathAssetRequestHandler(ResourceStreamer streamer,
045                                        AssetSource assetSource, String baseFolder,
046                                        ClasspathAssetProtectionRule classpathAssetProtectionRule)
047    {
048        this.streamer = streamer;
049        this.assetSource = assetSource;
050        this.baseFolder = baseFolder;
051        this.classpathAssetProtectionRule = classpathAssetProtectionRule;
052    }
053
054    public boolean handleAssetRequest(Request request, Response response, String extraPath) throws IOException
055    {
056        ChecksumPath path = new ChecksumPath(streamer, baseFolder, extraPath);
057        
058        final boolean handled;
059        if (classpathAssetProtectionRule.block(path.resourcePath)) 
060        {
061            handled = false;
062        }
063        else
064        {
065            Resource resource = assetSource.resourceForPath(path.resourcePath);
066    
067            handled = path.stream(resource);
068        }
069        return handled;
070    }
071}