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JFreeChart实现实时曲线图

2010-12-09 19:54 423 查看
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:
java 代码

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);

}

});

}

}

这两中方法都有一个问题,就是每实现一个图就要重新写一次,因为实时数据无法通过参数传进来,在想有没有可能通过setXXX()方式传进实时数据,那样的话就可以将实时曲线绘制类封装起来,而只需传递些参数即可(或者谁有更好的办法??)。
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