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: 

//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);
  }

 });
 }
} 

 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?

以上就是本文的全部内容,希望对大家的学习有所帮助,也希望大家多多支持脚本之家。

01-29 22:58