001// Copyright 2004, 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.asset;
016
017import java.io.InputStream;
018import java.net.URL;
019
020import org.apache.hivemind.ApplicationRuntimeException;
021import org.apache.hivemind.Location;
022import org.apache.hivemind.Resource;
023import org.apache.hivemind.util.ClasspathResource;
024import org.apache.hivemind.util.Defense;
025import org.apache.tapestry.engine.IEngineService;
026import org.apache.tapestry.engine.ILink;
027
028/**
029 * An implementation of {@link org.apache.tapestry.IAsset}for localizable assets within the JVM's
030 * classpath.
031 * <p>
032 * The localization code here is largely cut-and-paste from {@link ContextAsset}.
033 * 
034 * @author Howard Ship
035 */
036
037public class PrivateAsset extends AbstractAsset
038{
039    private IEngineService _assetService;
040
041    /**
042     * @deprecated To be removed (someday). Use
043     *             {@link #PrivateAsset(ClasspathResource, IEngineService, Location)}&nbsp;instead.
044     */
045    public PrivateAsset(ClasspathResource resourceLocation, Location location)
046    {
047        this(resourceLocation, null, location);
048    }
049
050    public PrivateAsset(ClasspathResource resourceLocation, IEngineService assetService,
051            Location location)
052    {
053        super(resourceLocation, location);
054
055        Defense.notNull(assetService, "assetService");
056
057        _assetService = assetService;
058    }
059
060    /**
061     * Gets the localized version of the resource. Build the URL for the resource. If possible, the
062     * application's {@link AssetExternalizerImpl}is located, to copy the resource to a directory
063     * visible to the web server.
064     */
065
066    public String buildURL()
067    {
068        String path = getResourceLocation().getPath();
069
070        ILink link = _assetService.getLink(false, path);
071
072        return link.getURL();
073    }
074
075    public InputStream getResourceAsStream()
076    {
077        Resource location = getResourceLocation();
078
079        try
080        {
081            URL url = location.getResourceURL();
082
083            return url.openStream();
084        }
085        catch (Exception ex)
086        {
087            throw new ApplicationRuntimeException(AssetMessages.noSuchResource(location.getPath()));
088        }
089    }
090
091}