001 /** 002 * ================================================ 003 * LibLoader : a free Java resource loading library 004 * ================================================ 005 * 006 * Project Info: http://reporting.pentaho.org/libloader/ 007 * 008 * (C) Copyright 2006, by Pentaho Corporation and Contributors. 009 * 010 * This library is free software; you can redistribute it and/or modify it under the terms 011 * of the GNU Lesser General Public License as published by the Free Software Foundation; 012 * either version 2.1 of the License, or (at your option) any later version. 013 * 014 * This library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; 015 * without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. 016 * See the GNU Lesser General Public License for more details. 017 * 018 * You should have received a copy of the GNU Lesser General Public License along with this 019 * library; if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330, 020 * Boston, MA 02111-1307, USA. 021 * 022 * [Java is a trademark or registered trademark of Sun Microsystems, Inc. 023 * in the United States and other countries.] 024 * 025 * 026 * ------------ 027 * $Id: ResourceLoader.java 2713 2007-04-01 13:43:18Z taqua $ 028 * ------------ 029 * (C) Copyright 2006, by Pentaho Corporation. 030 */ 031 package org.jfree.resourceloader; 032 033 import java.util.Map; 034 import java.net.URL; 035 036 /** 037 * A resource loader knows how to get binary rawdata from a location specified 038 * by an resource key. A resource key is a wrapper around any kind of data that 039 * is suitable to identify a resource location. The resource key can also hold 040 * configuration data for the factory. 041 * 042 * If the storage system is hierarchical, a new resource key can be derived from 043 * a given path-string. 044 * 045 * @author Thomas Morgner 046 */ 047 public interface ResourceLoader 048 { 049 /** 050 * Checks, whether this resource loader implementation was responsible for 051 * creating this key. 052 * 053 * @param key 054 * @return 055 */ 056 public boolean isSupportedKey (ResourceKey key); 057 058 /** 059 * Creates a new resource key from the given object and the factory keys. 060 * 061 * @param value 062 * @param factoryKeys 063 * @return the created key or null, if the format was not recognized. 064 * @throws ResourceKeyCreationException if creating the key failed. 065 */ 066 public ResourceKey createKey (Object value, 067 Map factoryKeys) 068 throws ResourceKeyCreationException; 069 070 /** 071 * Derives a new resource key from the given key. If neither a path nor new 072 * factory-keys are given, the parent key is returned. 073 * 074 * @param parent the parent 075 * @param path the derived path (can be null). 076 * @param factoryKeys the optional factory keys (can be null). 077 * @return the derived key. 078 * @throws ResourceKeyCreationException if the key cannot be derived for any 079 * reason. 080 */ 081 public ResourceKey deriveKey (ResourceKey parent, 082 String path, 083 Map factoryKeys) 084 throws ResourceKeyCreationException; 085 086 /** 087 * Loads the binary data represented by this key. 088 * 089 * @param key 090 * @return 091 * @throws ResourceLoadingException 092 */ 093 public ResourceData load (ResourceKey key) 094 throws ResourceLoadingException; 095 096 public void setResourceManager (ResourceManager manager); 097 098 public URL toURL (ResourceKey key); 099 }