001    // Copyright 2009, 2010 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.tapestry5.internal.services;
016    
017    import java.io.IOException;
018    
019    import org.apache.tapestry5.ioc.Resource;
020    
021    /**
022     * Responsible for converting a path into a {@link org.apache.tapestry5.ioc.Resource} that can be
023     * {@linkplain org.apache.tapestry5.internal.services.ResourceStreamer
024     * streamed to the client}. The path is on the classpath, but may have been changed to include a checksum (in
025     * certain cases).
026     * 
027     * @since 5.1.0.2
028     */
029    public interface AssetResourceLocator
030    {
031        /**
032         * For a complete classpath path, returns the Resource for the path. This include checking for a
033         * digest for protected files.
034         * 
035         * @return
036         *         resource corresponding to path (may be for a non-existent resource), or null if path is invalid (i.e.,
037         *         incorrect digest)
038         */
039        Resource findClasspathResourceForPath(String path) throws IOException;
040    }