Jfreechart中的半圆环图

如何在jfreechart中绘制半个坚果图，例如使用以下链接https://www.highcharts.com/demo/pie-semi-circle

这是我的代码

DefaultPieDataset dataset = new DefaultPieDataset( );

dataset.setValue("Safari-32", new Long( 32) );  dataset.setValue("Chrome-44", new Long( 44) ); 
dataset.setValue("Apple-24", new Long( 24) ); 
dataset.setValue("Google-75", new Long( 75) ); 
dataset.setValue("Michele", new Long( 97) );  dataset.setValue("Jony", new Long( 41) );

JFreeChart chart = ChartFactory.createRingChart("Chart title", dataset, true, false, false);
chart.setBackgroundPaint(Color.WHITE);
chart.setBorderVisible(false); 

RingPlot plots = (RingPlot) chart.getPlot();

Font font3 = new Font("Book Antiqua", Font.BOLD, 17); 



plots.setShadowPaint(null);
plots.setBackgroundPaint(null); 
plots.setOutlineVisible(false); 
plots.setLabelOutlinePaint(null);  
plots.setLabelBackgroundPaint(Color.WHITE);
plots.setCenterTextMode(CenterTextMode.FIXED);
String te = "334";
plots.setCenterText((String)te); plots.setCenterTextFont(font3);
plots.setLabelGenerator(null);  // Remove the labels from chart area

font3 = new Font("Book Antiqua", Font.PLAIN, 10); 
LegendTitle legend = chart.getLegend();
legend.setPosition(RectangleEdge.RIGHT); legend.setItemFont(font3); 

legend.setBorder(0, 0, 0, 0);



String filename = "D:\ad\do nut.jpg";
ChartUtilities.saveChartAsJPEG(new File(filename), chart, 250, 155);

这是我的代码，它生成一个完整的甜甜圈图表。我需要一个起始角度从180度到0度的甜甜圈

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解决方案

我需要一个起始角度从180度到0度的甜甜圈。

您可以使用父PiePlot方法setStartAngle()从180°开始。您可以使用透明颜色隐藏下半部分，如here所示，或使用所示here中的一种方法将其遮盖。OverlayLayout和透明白色如下图所示。

import java.awt.Color;
import java.awt.Dimension;
import java.awt.EventQueue;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.OverlayLayout;
import org.jfree.chart.ChartFactory;
import org.jfree.chart.ChartPanel;
import org.jfree.chart.JFreeChart;
import org.jfree.chart.plot.RingPlot;
import org.jfree.data.general.DefaultPieDataset;
import org.jfree.data.general.PieDataset;

public class RingChartTest {

    private PieDataset createDataset() {
        DefaultPieDataset dataset = new DefaultPieDataset();
        dataset.setValue("Safari", 75);
        dataset.setValue("Chrome", 60);
        dataset.setValue("FireFox", 45);
        dataset.setValue("", 180);
        return dataset;
    }

    private JFreeChart createChart(PieDataset dataset) {
        JFreeChart chart = ChartFactory.createRingChart(
            "Browser Share", dataset, true, false, false);
        RingPlot plot = (RingPlot) chart.getPlot();
        plot.setStartAngle(180);
        plot.setCircular(true);
        plot.setSimpleLabels(true);
        plot.setSectionDepth(0.5);
        plot.setBackgroundPaint(Color.WHITE);
        Color invisible = new Color(0xffffffff, true);
        plot.setSectionPaint("", invisible);
        plot.setSectionOutlinePaint("", invisible);
        plot.setShadowPaint(null);
        //plot.setLabelGenerator(null);
        return chart;
    }

    public JPanel createDemoPanel() {
        JFreeChart jfreechart = createChart(createDataset());
        ChartPanel chartPanel = new ChartPanel(jfreechart) {
            @Override
            public Dimension getPreferredSize() {
                return new Dimension(500, 400);
            }
        };
        chartPanel.setLayout(new OverlayLayout(chartPanel));
        JLabel label = new JLabel("BrowserShare");
        label.setFont(label.getFont().deriveFont(48.0f));
        label.setHorizontalAlignment(JLabel.CENTER);
        label.setVerticalAlignment(JLabel.CENTER);
        label.setAlignmentX(0.5f);
        label.setAlignmentY(0.75f);
        label.setOpaque(true);
        label.setBackground(Color.LIGHT_GRAY);
        chartPanel.add(label);
        return chartPanel;
    }

    public static void main(String args[]) {
        EventQueue.invokeLater(() -> {
            JFrame f = new JFrame("Ring Test");
            f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
            f.add(new RingChartTest().createDemoPanel());
            f.pack();
            f.setLocationRelativeTo(null);
            f.setVisible(true);
        });
    }
}