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; 016 017 import java.io.InputStream; 018 019 import org.apache.hivemind.Locatable; 020 import org.apache.hivemind.Resource; 021 022 /** 023 * Representation of a asset (GIF, JPEG, etc.) that may be owned by a {@link IComponent}. 024 * <p> 025 * Assets may be completely external (i.e., on some other web site), contained by the 026 * {@link javax.servlet.ServletContext}, or stored somewhere in the classpath. 027 * <p> 028 * In the latter two cases, the resource may be localized. 029 * 030 * @author Howard Lewis Ship 031 */ 032 033 public interface IAsset extends Locatable 034 { 035 /** 036 * Returns a URL for the asset, ready to be inserted into the output HTML. If the asset can be 037 * localized, the localized version (matching the {@link java.util.Locale}of the current 038 * {@link IPage page}) is returned. 039 * 040 * @throws ApplicationRuntimeException 041 * if the asset does not exist. 042 */ 043 044 public String buildURL(); 045 046 /** 047 * Accesses the localized version of the resource (if possible) and returns it as an input 048 * stream. A version of the resource localized to the current {@link IPage page}is returned. 049 * 050 * @throws ApplicationRuntimeException 051 * if the asset does not exist, or can't be read. 052 */ 053 054 public InputStream getResourceAsStream(); 055 056 /** 057 * Returns the underlying location of the asset. 058 */ 059 060 public Resource getResourceLocation(); 061 }