jfreechart customize piechart to show absolute values and percentages

Question

How can this compilable minimal code snippet example, which uses JFreeChart as plotting API, adapted in order to show both absoulte values AND percentages?

Answer 1

Use the MessageFormat symbol {1} for the absolute section value.

See StandardPieSectionLabelGenerator for details.

public class MyMinimalPieChartExample {

    private static final String KEY1 = "Datum 1";
    public static final String KEY2 = "Datum 2";

    public static void main(String[] args) {
        DefaultPieDataset dataset = new DefaultPieDataset();
        dataset.setValue(KEY1, 99);
        dataset.setValue(KEY2, 77);

        JFreeChart someChart = ChartFactory.createPieChart(
            "Header", dataset, true, true, false);
        PiePlot plot = (PiePlot) someChart.getPlot();
        plot.setSectionPaint(KEY1, Color.green);
        plot.setSectionPaint(KEY2, Color.red);
        plot.setExplodePercent(KEY1, 0.10);
        plot.setSimpleLabels(true);

        PieSectionLabelGenerator gen = new StandardPieSectionLabelGenerator(
            "{0}: {1} ({2})", new DecimalFormat("0"), new DecimalFormat("0%"));
        plot.setLabelGenerator(gen);

        JFrame f = new JFrame("Test");
        f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        f.add(new ChartPanel(someChart) {
            @Override
            public Dimension getPreferredSize() {
                return new Dimension(400, 300);
            }
        });
        f.pack();
        f.setLocationRelativeTo(null);
        f.setVisible(true);

    }
}