Java JFreeChart DynamicTimeSeriesCollection. How do I get my x-axis to show the current time?

Question

I've made a live graph using JFreeChart where it shows the temperature for a location every 10 seconds. However on the x-axis, it shows seconds instead of the current time (like 19:45 for example) for each temperature. How would I achieve showing the current time on the x-axis?

Here's my code based this 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

You've given your DateAxis a SimpleDateFormat override of "ss.SS", which shows seconds.milliseconds. You might want hour:minutes:seconds:

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