//RealTimeChart .java 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;  public class RealTimeChart extends ChartPanel implements Runnable {  private static TimeSeries timeSeries;  private long value=0;    public RealTimeChart(String chartContent,String title,String yaxisName)  {   super(createChart(chartContent,title,yaxisName));  }    private static JFreeChart createChart(String chartContent,String title,String yaxisName){   //創建時序圖對象   timeSeries = new TimeSeries(chartContent,Millisecond.class);   TimeSeriesCollection timeseriescollection = new TimeSeriesCollection(timeSeries);   JFreeChart jfreechart = ChartFactory.createTimeSeriesChart(title,"時間(秒)",yaxisName,timeseriescollection,true,true,false);   XYPlot xyplot = jfreechart.getXYPlot();   //縱坐標設定   ValueAxis valueaxis = xyplot.getDomainAxis();   //自動設置數據軸數據范圍   valueaxis.setAutoRange(true);   //數據軸固定數據范圍 30s   valueaxis.setFixedAutoRange(30000D);    valueaxis = xyplot.getRangeAxis();   //valueaxis.setRange(0.0D,200D);    return jfreechart;   }   public void run()  {   while(true)   {   try   {    timeSeries.add(new Millisecond(), randomNum());    Thread.sleep(300);   }   catch (InterruptedException e) { }   }    }    private long randomNum()  {    System.out.println((Math.random()*20+80));    return (long)(Math.random()*20+80);  } }  //Test.java import java.awt.BorderLayout; import java.awt.event.WindowAdapter; import java.awt.event.WindowEvent; import javax.swing.JFrame;  public class Test {   /**   * @param args   */  public static void main(String[] args)  {  JFrame frame=new JFrame("Test Chart");  RealTimeChart rtcp=new RealTimeChart("Random Data","隨機數","數值");  frame.getContentPane().add(rtcp,new BorderLayout().CENTER);  frame.pack();  frame.setVisible(true);  (new Thread(rtcp)).start();  frame.addWindowListener(new WindowAdapter()  {   public void windowClosing(WindowEvent windowevent)   {    System.exit(0);   }   });  } }