JFreeChart 实时曲线图

最近要用到实时曲线图，在网上大概找了一下，有两种实现方式，一种就是JFreeChart的官方实例MemoryUsageDemo.java.通过一个实现java.Swing.Timer的内部类，在其监听器中将实时数据添加进TimeSeries，由于Timer是会实时执行的，所以这个方法倒是没有什么问题，可以参考代码。
      另一种方式就是将实时类实现Runnable接口，在其run()方法中，通过无限循环将实时数据添加进TimeSeries，下面是较简单的实现代码：

此代码经过测试，可运行

//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){   
        //创建时序图对象   
        timeSeries = new TimeSeries(chartContent,Millisecond.class);   
        TimeSeriesCollection timeseriescollection = new TimeSeriesCollection(timeSeries);   
        JFreeChart jfreechart = ChartFactory.createTimeSeriesChart(title,"时间(秒)",yaxisName,timeseriescollection,true,true,false);   
        XYPlot xyplot = jfreechart.getXYPlot();   
        //纵坐标设定   
        ValueAxis valueaxis = xyplot.getDomainAxis();   
        //自动设置数据轴数据范围   
        valueaxis.setAutoRange(true);   
        //数据轴固定数据范围 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","随机数","数值");   
    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);   
        }   
   
    });   
    }   
}