import org.jfree.chart.JFreeChart;
import org.jfree.chart.ChartFactory;
import org.jfree.data.statistics.HistogramDataset;
import org.jfree.chart.plot.PlotOrientation;

import javax.swing.JFrame;
import java.awt.BorderLayout;
import org.jfree.chart.ChartPanel;

public class Test2_1 extends JFrame{
  public static void main(String[] args) {
    Test2_1 frame = new Test2_1();

    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    frame.setBounds(10, 10, 500, 500);
    frame.setTitle("グラフサンプル");
    frame.setVisible(true);
  }

  Test2_1(){
    JFreeChart chart = ChartFactory.createHistogram("成績分布", 
                                                    "得点",
                                                    "人数",
                                                    createData(),
                                                    PlotOrientation.VERTICAL, 
                                                    true, 
                                                    false, 
                                                    false);

    ChartPanel cpanel = new ChartPanel(chart);
    getContentPane().add(cpanel, BorderLayout.CENTER);
  }

  private HistogramDataset createData(){
    HistogramDataset data = new HistogramDataset();

    double[] values = {50d, 42d, 64d, 25d, 82d, 46d, 64d, 72d, 38d, 48d,
                       33d, 57d, 52d, 48d, 61d, 91d, 12d, 59d, 52d, 48d,
                       72d, 38d, 69d, 28d, 45d, 57d, 55d, 61d, 76d, 60d};

    data.addSeries("数学", values, 10);

    return data;
  }
}