Source for org.jfree.resourceloader.SimpleResource

   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: SimpleResource.java 3520 2007-10-16 10:34:47Z tmorgner $
  28:  * ------------
  29:  * (C) Copyright 2006, by Pentaho Corporation.
  30:  */
  31: package org.jfree.resourceloader;
  32: 
  33: /**
  34:  * A simple resource with only a single dependency.
  35:  *
  36:  * @author Thomas Morgner
  37:  */
  38: public class SimpleResource implements Resource
  39: {
  40:   private Object value;
  41:   private ResourceKey key;
  42:   private long version;
  43: 
  44:   public SimpleResource(final ResourceKey key,
  45:                         final Object value,
  46:                         final long version)
  47:   {
  48:     if (key == null)
  49:     {
  50:       throw new NullPointerException();
  51:     }
  52:     this.value = value;
  53:     this.key = key;
  54:     this.version = version;
  55:   }
  56: 
  57:   public Object getResource()
  58:   {
  59:     return value;
  60:   }
  61: 
  62:   public long getVersion(final ResourceKey key)
  63:   {
  64:     if (key.equals(this.key))
  65:     {
  66:       return version;
  67:     }
  68:     // -1 is the placeholder for: not known.
  69:     return -1;
  70:   }
  71: 
  72:   /**
  73:    * The primary source is also included in this set. The dependencies are given
  74:    * as ResourceKey objects. The keys itself do not hold any state information.
  75:    * <p/>
  76:    * The dependencies do not track deep dependencies. So if Resource A depends
  77:    * on Resource B which depends on Resource C, then A only knows about B, not
  78:    * C.
  79:    *
  80:    * @return
  81:    */
  82:   public ResourceKey[] getDependencies()
  83:   {
  84:     return new ResourceKey[]{getSource()};
  85:   }
  86: 
  87:   public ResourceKey getSource()
  88:   {
  89:     return key;
  90:   }
  91: }