Source for org.jfree.xml.factory.objects.ClassLoaderObjectDescription

   1: /* ========================================================================
   2:  * JCommon : a free general purpose class library for the Java(tm) platform
   3:  * ========================================================================
   4:  *
   5:  * (C) Copyright 2000-2005, by Object Refinery Limited and Contributors.
   6:  * 
   7:  * Project Info:  http://www.jfree.org/jcommon/index.html
   8:  *
   9:  * This library is free software; you can redistribute it and/or modify it 
  10:  * under the terms of the GNU Lesser General Public License as published by 
  11:  * the Free Software Foundation; either version 2.1 of the License, or 
  12:  * (at your option) any later version.
  13:  *
  14:  * This library is distributed in the hope that it will be useful, but 
  15:  * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY 
  16:  * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public 
  17:  * License for more details.
  18:  *
  19:  * You should have received a copy of the GNU Lesser General Public
  20:  * License along with this library; if not, write to the Free Software
  21:  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, 
  22:  * USA.  
  23:  *
  24:  * [Java is a trademark or registered trademark of Sun Microsystems, Inc. 
  25:  * in the United States and other countries.]
  26:  * 
  27:  * ---------------------------------
  28:  * ClassLoaderObjectDescription.java
  29:  * ---------------------------------
  30:  * (C)opyright 2003, 2004, by Thomas Morgner and Contributors.
  31:  *
  32:  * Original Author:  Thomas Morgner;
  33:  * Contributor(s):   David Gilbert (for Object Refinery Limited);
  34:  *
  35:  * $Id: ClassLoaderObjectDescription.java,v 1.5 2005/11/14 11:01:04 mungady Exp $
  36:  *
  37:  * Changes (from 19-Feb-2003)
  38:  * -------------------------
  39:  * 19-Feb-2003 : Added standard header and Javadocs (DG);
  40:  * 29-Apr-2003 : Distilled from the JFreeReport project and moved into JCommon
  41:  *
  42:  */
  43: 
  44: package org.jfree.xml.factory.objects;
  45: 
  46: import java.lang.reflect.Constructor;
  47: import java.lang.reflect.Modifier;
  48: 
  49: import org.jfree.util.ObjectUtilities;
  50: 
  51: /**
  52:  * An object-description for a class loader.
  53:  *
  54:  * @author Thomas Morgner
  55:  */
  56: public class ClassLoaderObjectDescription extends AbstractObjectDescription {
  57: 
  58:     /**
  59:      * Creates a new object description.
  60:      */
  61:     public ClassLoaderObjectDescription() {
  62:         super(Object.class);
  63:         setParameterDefinition("class", String.class);
  64:     }
  65: 
  66:     /**
  67:      * Creates an object based on this object description.
  68:      *
  69:      * @return The object.
  70:      */
  71:     public Object createObject() {
  72:         try {
  73:             final String o = (String) getParameter("class");
  74:             return ObjectUtilities.getClassLoader(getClass()).loadClass(o).newInstance();
  75:         }
  76:         catch (Exception e) {
  77:             return null;
  78:         }
  79:     }
  80: 
  81:     /**
  82:      * Sets the parameters of the object description to match the supplied object.
  83:      *
  84:      * @param o  the object.
  85:      *
  86:      * @throws ObjectFactoryException if there is a problem while reading the
  87:      * properties of the given object.
  88:      */
  89:     public void setParameterFromObject(final Object o) throws ObjectFactoryException {
  90:         if (o == null) {
  91:             throw new ObjectFactoryException("The Object is null.");
  92:         }
  93:         try {
  94:             final Constructor c = o.getClass().getConstructor(new Class[0]);
  95:             if (!Modifier.isPublic(c.getModifiers())) {
  96:                 throw new ObjectFactoryException
  97:                     ("The given object has no public default constructor. [" + o.getClass() + "]");
  98:             }
  99:             setParameter("class", o.getClass().getName());
 100:         }
 101:         catch (Exception e) {
 102:             throw new ObjectFactoryException
 103:                 ("The given object has no default constructor. [" + o.getClass() + "]", e);
 104:         }
 105:     }
 106: }