    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
    044    package org.jfree.xml.factory.objects;
    045
    046    import java.lang.reflect.Constructor;
    047    import java.lang.reflect.Modifier;
    048
    049    import org.jfree.util.ObjectUtilities;
    050
    051    /**
    052     * An object-description for a class loader.
    053     *
    054     * @author Thomas Morgner
    055     */
    056    public 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    }