    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 * ArrayObjectDescription.java
    029 * ---------------------------
    030 * (C)opyright 2003, 2004, by Thomas Morgner and Contributors.
    031 *
    032 * Original Author:  Thomas Morgner (taquera@sherito.org);
    033 * Contributor(s):   David Gilbert (for Object Refinery Limited);
    034 *
    035 * $Id: ArrayObjectDescription.java,v 1.4 2006/01/27 18:53:15 taqua Exp $
    036 *
    037 * Changes
    038 * -------
    039 * 14-Apr-2003 : Initial version
    040 * 29-Apr-2003 : Distilled from the JFreeReport project and moved into JCommon
    041 */
    042package org.jfree.xml.factory.objects;
    043
    044import java.lang.reflect.Array;
    045import java.util.ArrayList;
    046import java.util.Iterator;
    047
    048import org.jfree.util.Log;
    049
    050/**
    051 * Describes an Object- or primitive value array. This object description is
    052 * not intended to be created outside the ArrayClassFactory.
    053 *
    054 * @author Thomas Morgner
    055 */
    056public class ArrayObjectDescription extends AbstractObjectDescription {
    057
    058    /**
    059     * Constructs a new array objet description for the given array class.
    060     * <P>
    061     * Note:  throws <code>IllegalArgumentException</code> if the given class is no array.
    062     *
    063     * @param c the array class object.
    064     */
    065    public ArrayObjectDescription(final Class c) {
    066        super(c);
    067        if (!c.isArray()) {
    068            throw new IllegalArgumentException("Need an array class");
    069        }
    070    }
    071
    072    /**
    073     * Creates an object based on the description.
    074     *
    075     * @return The object.
    076     */
    077    public Object createObject() {
    078        try {
    079            final Integer size = (Integer) getParameter("size");
    080            if (size == null) {
    081                final ArrayList l = new ArrayList();
    082                int counter = 0;
    083                while (getParameterDefinition(String.valueOf(counter)) != null) {
    084                    final Object value = getParameter(String.valueOf(counter));
    085                    if (value == null) {
    086                        break;
    087                    }
    088
    089                    l.add(value);
    090                    counter += 1;
    091                }
    092
    093                final Object o = Array.newInstance
    094                    (getObjectClass().getComponentType(), l.size());
    095                for (int i = 0; i < l.size(); i++) {
    096                    Array.set(o, i, l.get(i));
    097                }
    098                return o;
    099            }
    100            else {
    101                // a size is given, so we can assume that all values are defined.
    102                final Object o = Array.newInstance
    103                    (getObjectClass().getComponentType(), size.intValue());
    104                for (int i = 0; i < size.intValue(); i++) {
    105                    Array.set(o, i, getParameter(String.valueOf(i)));
    106                }
    107                return o;
    108            }
    109        }
    110        catch (Exception ie) {
    111            Log.warn("Unable to instantiate Object", ie);
    112            return null;
    113        }
    114    }
    115
    116    /**
    117     * Sets the parameters of this description object to match the supplied object.
    118     *
    119     * @param o  the object.
    120     *
    121     * @throws ObjectFactoryException if there is a
    122     * problem while reading the properties of the given object.
    123     */
    124    public void setParameterFromObject(final Object o) throws ObjectFactoryException {
    125        if (o == null) {
    126            throw new ObjectFactoryException("Given object is null.");
    127        }
    128
    129        if (!o.getClass().isArray()) {
    130            throw new ObjectFactoryException("Given object is no array");
    131        }
    132
    133        if (!getObjectClass().isAssignableFrom(o.getClass())) {
    134            throw new ObjectFactoryException("Given object is incompatible with base class");
    135        }
    136
    137        final int size = Array.getLength(o);
    138        setParameter("size", new Integer(size));
    139        for (int i = 0; i < size; i++) {
    140            setParameter(String.valueOf(i), Array.get(o, i));
    141        }
    142    }
    143
    144    /**
    145     * Tries to parse the given parameter string into a positive integer.
    146     * Returns -1 if the parsing failed for some reason.
    147     *
    148     * @param name the name of the parameter.
    149     * @return the parsed int value or -1 on errors.
    150     */
    151    private int parseParameterName(final String name) {
    152        try {
    153            return Integer.parseInt(name);
    154        }
    155        catch (Exception e) {
    156            return -1;
    157        }
    158    }
    159
    160    /**
    161     * Returns a parameter definition. If the parameter is invalid, this
    162     * function returns null.
    163     *
    164     * @param name  the definition name.
    165     *
    166     * @return The parameter class or null, if the parameter is not defined.
    167     */
    168    public Class getParameterDefinition(final String name) {
    169        if (name.equals("size")) {
    170            return Integer.TYPE;
    171        }
    172        final int par = parseParameterName(name);
    173        if (par < 0) {
    174            return null;
    175        }
    176        return getObjectClass().getComponentType();
    177    }
    178
    179    /**
    180     * Returns an iterator for the parameter names.
    181     *
    182     * @return The iterator.
    183     */
    184    public Iterator getParameterNames() {
    185        final Integer size = (Integer) getParameter("size");
    186        if (size == null) {
    187            return getDefinedParameterNames();
    188        }
    189        else {
    190            final ArrayList l = new ArrayList();
    191            l.add("size");
    192            for (int i = 0; i < size.intValue(); i++) {
    193                l.add(String.valueOf(i));
    194            }
    195            return l.iterator();
    196        }
    197    }
    198
    199    /**
    200     * Returns a new instance of the object description.
    201     *
    202     * @return The object description.
    203     */
    204    public ObjectDescription getInstance() {
    205        return new ArrayObjectDescription(getObjectClass());
    206    }
    207}