Source for org.jfree.resourceloader.ResourceLoader

   1: /**
   2:  * ================================================
   3:  * LibLoader : a free Java resource loading library
   4:  * ================================================
   5:  *
   6:  * Project Info:  http://reporting.pentaho.org/libloader/
   7:  *
   8:  * (C) Copyright 2006, by Pentaho Corporation and Contributors.
   9:  *
  10:  * This library is free software; you can redistribute it and/or modify it under the terms
  11:  * of the GNU Lesser General Public License as published by the Free Software Foundation;
  12:  * either version 2.1 of the License, or (at your option) any later version.
  13:  *
  14:  * This library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
  15:  * without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
  16:  * See the GNU Lesser General Public License for more details.
  17:  *
  18:  * You should have received a copy of the GNU Lesser General Public License along with this
  19:  * library; if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330,
  20:  * Boston, MA 02111-1307, USA.
  21:  *
  22:  * [Java is a trademark or registered trademark of Sun Microsystems, Inc.
  23:  * in the United States and other countries.]
  24:  *
  25:  *
  26:  * ------------
  27:  * $Id: ResourceLoader.java 2713 2007-04-01 13:43:18Z taqua $
  28:  * ------------
  29:  * (C) Copyright 2006, by Pentaho Corporation.
  30:  */
  31: package org.jfree.resourceloader;
  32: 
  33: import java.util.Map;
  34: import java.net.URL;
  35: 
  36: /**
  37:  * A resource loader knows how to get binary rawdata from a location specified
  38:  * by an resource key. A resource key is a wrapper around any kind of data that
  39:  * is suitable to identify a resource location. The resource key can also hold
  40:  * configuration data for the factory.
  41:  *
  42:  * If the storage system is hierarchical, a new resource key can be derived from
  43:  * a given path-string.
  44:  *
  45:  * @author Thomas Morgner
  46:  */
  47: public interface ResourceLoader
  48: {
  49:   /**
  50:    * Checks, whether this resource loader implementation was responsible for
  51:    * creating this key.
  52:    *
  53:    * @param key
  54:    * @return
  55:    */
  56:   public boolean isSupportedKey (ResourceKey key);
  57: 
  58:   /**
  59:    * Creates a new resource key from the given object and the factory keys.
  60:    *
  61:    * @param value
  62:    * @param factoryKeys
  63:    * @return the created key or null, if the format was not recognized.
  64:    * @throws ResourceKeyCreationException if creating the key failed.
  65:    */
  66:   public ResourceKey createKey (Object value,
  67:                                 Map factoryKeys)
  68:       throws ResourceKeyCreationException;
  69: 
  70:   /**
  71:    * Derives a new resource key from the given key. If neither a path nor new
  72:    * factory-keys are given, the parent key is returned.
  73:    *
  74:    * @param parent the parent
  75:    * @param path the derived path (can be null).
  76:    * @param factoryKeys the optional factory keys (can be null).
  77:    * @return the derived key.
  78:    * @throws ResourceKeyCreationException if the key cannot be derived for any
  79:    * reason.
  80:    */
  81:   public ResourceKey deriveKey (ResourceKey parent,
  82:                                 String path,
  83:                                 Map factoryKeys)
  84:       throws ResourceKeyCreationException;
  85: 
  86:   /**
  87:    * Loads the binary data represented by this key.
  88:    *
  89:    * @param key
  90:    * @return
  91:    * @throws ResourceLoadingException
  92:    */
  93:   public ResourceData load (ResourceKey key)
  94:       throws ResourceLoadingException;
  95: 
  96:   public void setResourceManager (ResourceManager manager);
  97: 
  98:   public URL toURL (ResourceKey key);
  99: }