    001/* ========================================================================
    002 * JCommon : a free general purpose class library for the Java(tm) platform
    003 * ========================================================================
    004 *
    005 * (C) Copyright 2000-2005, by Object Refinery Limited and Contributors.
    006 *
    007 * Project Info:  http://www.jfree.org/jcommon/index.html
    008 *
    009 * This library is free software; you can redistribute it and/or modify it
    010 * under the terms of the GNU Lesser General Public License as published by
    011 * the Free Software Foundation; either version 2.1 of the License, or
    012 * (at your option) any later version.
    013 *
    014 * This library is distributed in the hope that it will be useful, but
    015 * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
    016 * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
    017 * License for more details.
    018 *
    019 * You should have received a copy of the GNU Lesser General Public
    020 * License along with this library; if not, write to the Free Software
    021 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301,
    022 * USA.
    023 *
    024 * [Java is a trademark or registered trademark of Sun Microsystems, Inc.
    025 * in the United States and other countries.]
    026 *
    027 * ---------------------------------
    028 * ClassLoaderObjectDescription.java
    029 * ---------------------------------
    030 * (C)opyright 2003, 2004, by Thomas Morgner and Contributors.
    031 *
    032 * Original Author:  Thomas Morgner;
    033 * Contributor(s):   David Gilbert (for Object Refinery Limited);
    034 *
    035 * $Id: ClassLoaderObjectDescription.java,v 1.5 2005/11/14 11:01:04 mungady Exp $
    036 *
    037 * Changes (from 19-Feb-2003)
    038 * -------------------------
    039 * 19-Feb-2003 : Added standard header and Javadocs (DG);
    040 * 29-Apr-2003 : Distilled from the JFreeReport project and moved into JCommon
    041 *
    042 */
    043
    044package org.jfree.xml.factory.objects;
    045
    046import java.lang.reflect.Constructor;
    047import java.lang.reflect.Modifier;
    048
    049import org.jfree.util.ObjectUtilities;
    050
    051/**
    052 * An object-description for a class loader.
    053 *
    054 * @author Thomas Morgner
    055 */
    056public class ClassLoaderObjectDescription extends AbstractObjectDescription {
    057
    058    /**
    059     * Creates a new object description.
    060     */
    061    public ClassLoaderObjectDescription() {
    062        super(Object.class);
    063        setParameterDefinition("class", String.class);
    064    }
    065
    066    /**
    067     * Creates an object based on this object description.
    068     *
    069     * @return The object.
    070     */
    071    public Object createObject() {
    072        try {
    073            final String o = (String) getParameter("class");
    074            return ObjectUtilities.getClassLoader(getClass()).loadClass(o).newInstance();
    075        }
    076        catch (Exception e) {
    077            return null;
    078        }
    079    }
    080
    081    /**
    082     * Sets the parameters of the object description to match the supplied object.
    083     *
    084     * @param o  the object.
    085     *
    086     * @throws ObjectFactoryException if there is a problem while reading the
    087     * properties of the given object.
    088     */
    089    public void setParameterFromObject(final Object o) throws ObjectFactoryException {
    090        if (o == null) {
    091            throw new ObjectFactoryException("The Object is null.");
    092        }
    093        try {
    094            final Constructor c = o.getClass().getConstructor(new Class[0]);
    095            if (!Modifier.isPublic(c.getModifiers())) {
    096                throw new ObjectFactoryException
    097                    ("The given object has no public default constructor. [" + o.getClass() + "]");
    098            }
    099            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}