Java JFreeChart DynamicTimeSeriesCollection。如何让我的x轴显示当前时间？

Question

我使用JFreeChart创建了一个实时图表，它每隔10秒显示一个位置的温度。但是在x轴上，它显示每个温度的秒而不是当前时间（例如19:45）。如何在x轴上显示当前时间？

以下是我的代码example：

public class DynamicTimeSeriesChart extends JPanel {

TestWeatherTimeLapseService getTemp = new TestWeatherTimeLapseService();  //gets temperature

private final DynamicTimeSeriesCollection dataset;
private final JFreeChart chart;

public DynamicTimeSeriesChart(final String title) {


    dataset = new DynamicTimeSeriesCollection(1, 10000, new Second());
    Date date = new Date();

    dataset.setTimeBase(new Second(date));
    dataset.addSeries(new float[1], 0, title);

    chart = ChartFactory.createTimeSeriesChart(
        title, "Time", title, dataset, true, true, false);
    final XYPlot plot = chart.getXYPlot();
    DateAxis axis = (DateAxis) plot.getDomainAxis();
    axis.setFixedAutoRange(10000);
    axis.setDateFormatOverride(new SimpleDateFormat("ss.SS"));
    final ChartPanel chartPanel = new ChartPanel(chart);
    chartPanel.setMouseWheelEnabled(true);
    add(chartPanel);
    chart.getXYPlot().setDomainPannable(true);
}

public void update() {
    float[] newData = new float[1];
    String currTemperature="";
    try {
         currTemperature=getTemp.getWeatherData("Laverton")[1];     //get temperature of laverton
    } catch (Exception e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }
    float number = Float.parseFloat(currTemperature);
    dataset.advanceTime();
    newData[0] = number;
    dataset.appendData(newData);
}



public static void main(String[] args) {

    EventQueue.invokeLater(new Runnable() {

        @Override
        public void run() {

            JFrame frame = new JFrame("testing");
            frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
            final DynamicTimeSeriesChart chart
                = new DynamicTimeSeriesChart("Temperature");
            frame.add(chart);
            frame.pack();
            Timer timer = new Timer(10000, new ActionListener() {

                @Override
                public void actionPerformed(ActionEvent e) {
                    chart.update();
                }
            });
            timer.start();
            frame.setVisible(true);
        }
    });
}}  

Answer 1

您已DateAxis SimpleDateFormat覆盖"ss.SS"，其中显示seconds.milliseconds。您可能需要hour:minutes:seconds：

axis.setDateFormatOverride(new SimpleDateFormat("HH:mm.ss"));