jfreechart example source code file (PieDatasetHandler.java)

This example jfreechart source code file (PieDatasetHandler.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Java - jfreechart tags/keywords

datasettags, defaulthandler, defaulthandler, defaultpiedataset, itemhandler, itemhandler, number, piedataset, piedatasethandler, piedatasethandler, roothandler, sax, saxexception, string, string

The jfreechart PieDatasetHandler.java source code

/* ===========================================================
 * JFreeChart : a free chart library for the Java(tm) platform
 * ===========================================================
 *
 * (C) Copyright 2000-2008, by Object Refinery Limited and Contributors.
 *
 * Project Info:  http://www.jfree.org/jfreechart/index.html
 *
 * This library is free software; you can redistribute it and/or modify it
 * under the terms of the GNU Lesser General Public License as published by
 * the Free Software Foundation; either version 2.1 of the License, or
 * (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
 * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
 * License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301,
 * USA.
 *
 * [Java is a trademark or registered trademark of Sun Microsystems, Inc.
 * in the United States and other countries.]
 *
 * ----------------------
 * PieDatasetHandler.java
 * ----------------------
 * (C) Copyright 2003-2008, by Object Refinery Limited and Contributors.
 *
 * Original Author:  David Gilbert (for Object Refinery Limited);
 * Contributor(s):   -;
 *
 * Changes
 * -------
 * 23-Jan-2003 : Version 1 (DG);
 *
 */

package org.jfree.data.xml;

import org.jfree.data.general.DefaultPieDataset;
import org.jfree.data.general.PieDataset;
import org.xml.sax.Attributes;
import org.xml.sax.SAXException;
import org.xml.sax.helpers.DefaultHandler;

/**
 * A SAX handler for reading a {@link PieDataset} from an XML file.
 */
public class PieDatasetHandler extends RootHandler implements DatasetTags {

    /** The pie dataset under construction. */
    private DefaultPieDataset dataset;

    /**
     * Default constructor.
     */
    public PieDatasetHandler() {
        this.dataset = null;
    }

    /**
     * Returns the dataset.
     *
     * @return The dataset.
     */
    public PieDataset getDataset() {
        return this.dataset;
    }

    /**
     * Adds an item to the dataset under construction.
     *
     * @param key  the key.
     * @param value  the value.
     */
    public void addItem(Comparable key, Number value) {
        this.dataset.setValue(key, value);
    }

    /**
     * Starts an element.
     *
     * @param namespaceURI  the namespace.
     * @param localName  the element name.
     * @param qName  the element name.
     * @param atts  the element attributes.
     *
     * @throws SAXException for errors.
     */
    public void startElement(String namespaceURI,
                             String localName,
                             String qName,
                             Attributes atts) throws SAXException {

        DefaultHandler current = getCurrentHandler();
        if (current != this) {
            current.startElement(namespaceURI, localName, qName, atts);
        }
        else if (qName.equals(PIEDATASET_TAG)) {
            this.dataset = new DefaultPieDataset();
        }
        else if (qName.equals(ITEM_TAG)) {
            ItemHandler subhandler = new ItemHandler(this, this);
            getSubHandlers().push(subhandler);
            subhandler.startElement(namespaceURI, localName, qName, atts);
        }

    }

    /**
     * The end of an element.
     *
     * @param namespaceURI  the namespace.
     * @param localName  the element name.
     * @param qName  the element name.
     *
     * @throws SAXException for errors.
     */
    public void endElement(String namespaceURI,
                           String localName,
                           String qName) throws SAXException {

        DefaultHandler current = getCurrentHandler();
        if (current != this) {
            current.endElement(namespaceURI, localName, qName);
        }

    }

}