JFreeChart-Pie Chart

A pie chart is a circular graph which is divided into sectors in which the area of each sector represents the size of the data.

The following images show some of the demo versions of pie chart incorporated in JFreeChart library:

Pie Chart Demo 1:

Pie Chart Demo 2:

Pie Chart Demo 4:

JFreeChart Pie Chart Demo 4

Pie Chart example

Let us consider a sample data of marks distribution for a class.

Marks Range	Number of Students
80-100	120
60-79	80
40-59	20
20-39	7
0-19	3

The following codes create a pie chart from the above sample data:

PieChartExample.java

import java.text.DecimalFormat;

import javax.swing.JFrame;
import javax.swing.SwingUtilities;
import javax.swing.WindowConstants;

import org.jfree.chart.ChartFactory;
import org.jfree.chart.ChartPanel;
import org.jfree.chart.JFreeChart;
import org.jfree.chart.labels.PieSectionLabelGenerator;
import org.jfree.chart.labels.StandardPieSectionLabelGenerator;
import org.jfree.chart.plot.PiePlot;
import org.jfree.data.general.DefaultPieDataset;
import org.jfree.data.general.PieDataset;
public class PieChartExample extends JFrame {
  private static final long serialVersionUID = 6294689542092367723L;

  public PieChartExample(String title) {
    super(title);

    // Create dataset
    PieDataset dataset = createDataset();

    // Create chart
    JFreeChart chart = ChartFactory.createPieChart(
        "Pie Chart Example",
        dataset,
        true, 
        true,
        false);

    //Format Label
    PieSectionLabelGenerator labelGenerator = new StandardPieSectionLabelGenerator(
        "Marks {0} : ({2})", new DecimalFormat("0"), new DecimalFormat("0%"));
    ((PiePlot) chart.getPlot()).setLabelGenerator(labelGenerator);
    
    // Create Panel
    ChartPanel panel = new ChartPanel(chart);
    setContentPane(panel);
  }

  private PieDataset createDataset() {

    DefaultPieDataset dataset=new DefaultPieDataset();
    dataset.setValue("80-100", 120);
    dataset.setValue("60-79", 80);
    dataset.setValue("40-59", 20);
    dataset.setValue("20-39", 7);
    dataset.setValue("0-19", 3);
    return dataset;
  }

  public static void main(String[] args) {
    SwingUtilities.invokeLater(() -> {
      PieChartExample example = new PieChartExample(?Pie Chart Example?);
      example.setSize(800, 400);
      example.setLocationRelativeTo(null);
      example.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
      example.setVisible(true);
    });
  }
}

Output: