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. 014 015 package org.apache.tapestry.asset; 016 017 import java.io.InputStream; 018 import java.net.URL; 019 020 import org.apache.hivemind.ApplicationRuntimeException; 021 import org.apache.hivemind.Location; 022 import org.apache.hivemind.Resource; 023 import org.apache.hivemind.util.Defense; 024 import org.apache.tapestry.IAsset; 025 import org.apache.tapestry.Tapestry; 026 027 /** 028 * An asset whose path is relative to the {@link javax.servlet.ServletContext}containing the 029 * application. 030 * 031 * @author Howard Lewis Ship 032 */ 033 034 public class ContextAsset extends AbstractAsset implements IAsset 035 { 036 private String _contextPath; 037 038 private String _resolvedURL; 039 040 public ContextAsset(String contextPath, Resource resource, Location location) 041 { 042 super(resource, location); 043 044 Defense.notNull(contextPath, "contextPath"); 045 046 _contextPath = contextPath; 047 } 048 049 /** 050 * Generates a URL for the client to retrieve the asset. The context path is prepended to the 051 * asset path, which means that assets deployed inside web applications will still work (if 052 * things are configured properly). 053 */ 054 055 public String buildURL() 056 { 057 if (_resolvedURL == null) 058 _resolvedURL = _contextPath + getResourceLocation().getPath(); 059 060 return _resolvedURL; 061 } 062 063 public InputStream getResourceAsStream() 064 { 065 try 066 { 067 URL url = getResourceLocation().getResourceURL(); 068 069 return url.openStream(); 070 } 071 catch (Exception ex) 072 { 073 throw new ApplicationRuntimeException(Tapestry.format( 074 "ContextAsset.resource-missing", 075 getResourceLocation()), ex); 076 } 077 } 078 }