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.internal.services.ResourceStreamer;
018import org.apache.tapestry5.ioc.Resource;
019import org.apache.tapestry5.services.AssetSource;
020import org.apache.tapestry5.services.ClasspathAssetAliasManager;
021import org.apache.tapestry5.services.ClasspathAssetProtectionRule;
022import org.apache.tapestry5.services.Request;
023import org.apache.tapestry5.services.Response;
024import org.apache.tapestry5.services.assets.AssetRequestHandler;
025import org.slf4j.Logger;
026import org.slf4j.LoggerFactory;
027
028import java.io.IOException;
029
030/**
031 * A handler for asset requests for classpath assets (within a specific folder).
032 * Each mapping of the {@link ClasspathAssetAliasManager} gets one of these.
033 *
034 * @since 5.2.0
035 */
036public class ClasspathAssetRequestHandler implements AssetRequestHandler
037{
038    
039    private final static Logger LOGGER = LoggerFactory.getLogger(ClasspathAssetRequestHandler.class);
040    
041    private final ResourceStreamer streamer;
042
043    private final AssetSource assetSource;
044    
045    private final String baseFolder;
046    
047    private final ClasspathAssetProtectionRule classpathAssetProtectionRule;
048
049    public ClasspathAssetRequestHandler(ResourceStreamer streamer,
050                                        AssetSource assetSource, String baseFolder,
051                                        ClasspathAssetProtectionRule classpathAssetProtectionRule)
052    {
053        this.streamer = streamer;
054        this.assetSource = assetSource;
055        this.baseFolder = baseFolder;
056        this.classpathAssetProtectionRule = classpathAssetProtectionRule;
057    }
058
059    public boolean handleAssetRequest(Request request, Response response, String extraPath) throws IOException
060    {
061        ChecksumPath path = new ChecksumPath(streamer, baseFolder, extraPath);
062        
063        final boolean handled;
064        if (classpathAssetProtectionRule.block(path.resourcePath) && !path.resourcePath.equals(ChecksumPath.NON_EXISTING_RESOURCE)) 
065        {
066            if (LOGGER.isWarnEnabled()) 
067            {
068                LOGGER.warn("Blocked request for classpath asset '" + path.resourcePath + 
069                        "'. Contribute a new ClasspathAssetProtectionRule if you need this asset to be publicly accessible.");
070            }
071            handled = false;
072        }
073        else
074        {
075            Resource resource = assetSource.resourceForPath(path.resourcePath);
076    
077            handled = path.stream(resource);
078        }
079        return handled;
080    }
081}