java - 从 XML 保存/加载 jFreechart TimeSeriesCollection 图表

Question

我正在使用这个 exemple将随机动态数据放入 TimeSeriesCollection 图表。

我的问题是我找不到如何:

1- 当旧数据(最后一小时)通过 View 区域的左边界(因为数据点从右向左移动)时，只需通过实现水平滚动条。

2- 当我想要所有数据的历史记录时，XML 是保存数据的好选择吗？

public class DynamicDataDemo extends ApplicationFrame  {
    /** The time series data. */
    private TimeSeries series;

    /** The most recent value added. */
    private double lastValue = 100.0;


public DynamicDataDemo(final String title) {

    super(title);
    this.series = new TimeSeries("Random Data", Millisecond.class);
    final TimeSeriesCollection dataset = new TimeSeriesCollection(this.series);
    final JFreeChart chart = createChart(dataset);

    final ChartPanel chartPanel = new ChartPanel(chart);

    final JPanel content = new JPanel(new BorderLayout());
    content.add(chartPanel);
    chartPanel.setPreferredSize(new java.awt.Dimension(500, 270));
    setContentPane(content);

}


private JFreeChart createChart(final XYDataset dataset) {
    final JFreeChart result = ChartFactory.createTimeSeriesChart(
        "Dynamic Data Demo", 
        "Time", 
        "Value",
        dataset, 
        true, 
        true, 
        false
    );
    final XYPlot plot = result.getXYPlot();
    ValueAxis axis = plot.getDomainAxis();
    axis.setAutoRange(true);
    axis.setFixedAutoRange(60000.0);  // 60 seconds
    axis = plot.getRangeAxis();
    axis.setRange(0.0, 200.0); 
    return result;
}


public void go() {

        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);

}


public static void main(final String[] args) throws InterruptedException {

    final DynamicDataDemo demo = new DynamicDataDemo("Dynamic Data Demo");
    demo.pack();
    RefineryUtilities.centerFrameOnScreen(demo);
    demo.setVisible(true);

    while(true){

        demo.go();
        Thread.currentThread().sleep(1000);
    }

}



}

Answer 1

1. example使用 default values在 TimeSeries 中指定最大项目年龄和数量。您需要更改它们以满足您的要求。

2. XML 很好，但对于高费率来说它太庞大了；相应地计划。

另见 example它使用 javax.swing.Timer 来避免阻塞事件调度线程。