Java tutorial
/* =========================================================== * JFreeChart : a free chart library for the Java(tm) platform * =========================================================== * * (C) Copyright 2000-2004, 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., 59 Temple Place, Suite 330, * Boston, MA 02111-1307, USA. * * [Java is a trademark or registered trademark of Sun Microsystems, Inc. * in the United States and other countries.] * * ------------------- * EmptyXYDataset.java * ------------------- * (C) Copyright 2001-2004, by Object Refinery Limited. * * Original Author: David Gilbert (for Object Refinery Limited). * Contributor(s): -; * * $Id: EmptyXYDataset.java,v 1.7 2004/05/06 07:53:50 mungady Exp $ * * Changes * ------- * 22-Nov-2001 : Version 1 (DG); * 10-Oct-2002 : Fixed errors reported by Checkstyle (DG); * 05-May-2004 : Now extends AbstractXYDataset (DG); * */ package org.jfree.chart.demo; import org.jfree.data.xy.AbstractXYDataset; import org.jfree.data.xy.XYDataset; /** * An empty dataset for testing purposes. * */ public class EmptyXYDataset extends AbstractXYDataset implements XYDataset { /** * Default constructor. */ public EmptyXYDataset() { super(); } /** * Returns the x-value for the specified series and item. * * @param series the series (zero-based index). * @param item the item (zero-based index). * * @return the x-value (always null for this class). */ public double getXValue(final int series, final int item) { return 0; } /** * Returns the y-value for the specified series and item. * * @param series the series (zero-based index). * @param item the item (zero-based index). * * @return the y-value (always null for this class). */ public double getYValue(final int series, final int item) { return 0; } /** * Returns the number of series in the dataset. * * @return the series count (always zero for this class). */ public int getSeriesCount() { return 0; } /** * Returns the name of the series. * * @param series the series (zero-based index). * * @return the name of the series (always null in this class). */ public String getSeriesName(final int series) { return null; } /** * Returns the number of items in the specified series. * * @param series the series (zero-based index). * * @return the item count (always zero in this class). */ public int getItemCount(final int series) { return 0; } /* (non-Javadoc) * @see org.jfree.data.general.AbstractSeriesDataset#getSeriesKey(int) */ public Comparable getSeriesKey(int series) { // TODO Auto-generated method stub return null; } /* (non-Javadoc) * @see org.jfree.data.xy.XYDataset#getX(int, int) */ public Number getX(int series, int item) { // TODO Auto-generated method stub return null; } /* (non-Javadoc) * @see org.jfree.data.xy.XYDataset#getY(int, int) */ public Number getY(int series, int item) { // TODO Auto-generated method stub return null; } }