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.] * * ----------------------- * SerializationTest1.java * ----------------------- * (C) Copyright 2004, by Object Refinery Limited. * * Original Author: David Gilbert (for Object Refinery Limited). * Contributor(s): -; * * $Id: SerializationTest1.java,v 1.5 2004/04/30 11:22:07 mungady Exp $ * * Changes * ------- * 02-Mar-2004 : Version 1 (DG); * */ package org.jfree.chart.demo; import java.awt.BorderLayout; import java.awt.event.ActionEvent; import java.awt.event.ActionListener; import java.io.ByteArrayInputStream; import java.io.ByteArrayOutputStream; import java.io.ObjectInput; import java.io.ObjectInputStream; import java.io.ObjectOutput; import java.io.ObjectOutputStream; import javax.swing.JButton; import javax.swing.JPanel; import org.jfree.chart.ChartFactory; import org.jfree.chart.ChartPanel; import org.jfree.chart.JFreeChart; import org.jfree.chart.axis.ValueAxis; import org.jfree.chart.plot.XYPlot; import org.jfree.data.time.Millisecond; import org.jfree.data.time.TimeSeries; import org.jfree.data.time.TimeSeriesCollection; import org.jfree.data.xy.XYDataset; import org.jfree.ui.ApplicationFrame; import org.jfree.ui.RefineryUtilities; /** * Based on the DynamicDataDemo class, this demo serializes and deserializes the chart * before displaying it - the idea is that this confirms that the serialization process * returns a working chart. * */ public class SerializationTest1 extends ApplicationFrame implements ActionListener { /** The time series data. */ private TimeSeries series; /** The most recent value added. */ private double lastValue = 100.0; /** * Constructs a new demonstration application. * * @param title the frame title. */ public SerializationTest1(final String title) { super(title); this.series = new TimeSeries("Random Data", Millisecond.class); TimeSeriesCollection dataset = new TimeSeriesCollection(this.series); JFreeChart chart = createChart(dataset); // SERIALIZE - DESERIALIZE for testing purposes JFreeChart deserializedChart = null; try { final ByteArrayOutputStream buffer = new ByteArrayOutputStream(); final ObjectOutput out = new ObjectOutputStream(buffer); out.writeObject(chart); out.close(); chart = null; dataset = null; this.series = null; System.gc(); final ObjectInput in = new ObjectInputStream(new ByteArrayInputStream(buffer.toByteArray())); deserializedChart = (JFreeChart) in.readObject(); in.close(); } catch (Exception e) { e.printStackTrace(); } final TimeSeriesCollection c = (TimeSeriesCollection) deserializedChart.getXYPlot().getDataset(); this.series = c.getSeries(0); // FINISHED TEST final ChartPanel chartPanel = new ChartPanel(deserializedChart); final JButton button = new JButton("Add New Data Item"); button.setActionCommand("ADD_DATA"); button.addActionListener(this); final JPanel content = new JPanel(new BorderLayout()); content.add(chartPanel); content.add(button, BorderLayout.SOUTH); chartPanel.setPreferredSize(new java.awt.Dimension(500, 270)); setContentPane(content); } /** * Creates a sample chart. * * @param dataset the dataset. * * @return A sample chart. */ private JFreeChart createChart(final XYDataset dataset) { final JFreeChart result = ChartFactory.createTimeSeriesChart("Serialization Test 1", "Time", "Value", dataset, true, true, false); final XYPlot plot = result.getXYPlot(); final ValueAxis axis = plot.getDomainAxis(); axis.setAutoRange(true); axis.setFixedAutoRange(60000.0); // 60 seconds return result; } /** * Handles a click on the button by adding new (random) data. * * @param e the action event. */ public void actionPerformed(final ActionEvent e) { if (e.getActionCommand().equals("ADD_DATA")) { final double factor = 0.90 + 0.2 * Math.random(); this.lastValue = this.lastValue * factor; final Millisecond now = new Millisecond(); System.out.println("Now = " + now.toString()); this.series.add(new Millisecond(), this.lastValue); } } /** * Starting point for the demonstration application. * * @param args ignored. */ public static void main(final String[] args) { final SerializationTest1 demo = new SerializationTest1("Serialization Test 1"); demo.pack(); RefineryUtilities.centerFrameOnScreen(demo); demo.setVisible(true); } }