nuage de points dans jfreechart à partir de la base de données

Cet exemple complet crée une table de base de données appropriée en mémoire, l'interroge dans un JDBCXYDataset et affiche le jeu de données dans un nuage de points. Notez comment la première colonne devient le domaine, tandis que les colonnes successives deviennent des séries individuelles.

import java.awt.EventQueue;
import java.sql.Connection;
import java.sql.Date;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.Calendar;
import java.util.Random;
import javax.swing.JFrame;
import org.jfree.chart.ChartFactory;
import org.jfree.chart.ChartPanel;
import org.jfree.chart.JFreeChart;
import org.jfree.chart.axis.DateAxis;
import org.jfree.chart.plot.PlotOrientation;
import org.jfree.chart.plot.XYPlot;
import org.jfree.data.jdbc.JDBCXYDataset;

/**
 * @see http://stackoverflow.com/a/24592754/230513
 */
public class JDBCTest {

    private static final int N = 30;
    private static final Random r = new Random();

    private void display() {
        JFrame f = new JFrame("JDBCTest");
        f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        JDBCXYDataset jds = createDataset();
        JFreeChart chart = ChartFactory.createScatterPlot("Inventory",
            "Date", "Count", jds, PlotOrientation.VERTICAL, true, true, false);
        XYPlot plot = chart.getXYPlot();
        plot.setDomainAxis(new DateAxis("Date"));
        f.add(new ChartPanel(chart));
        f.pack();
        f.setLocationRelativeTo(null);
        f.setVisible(true);
        for (int i = 0; i < jds.getItemCount(); i++) {
            System.out.println(new Date(jds.getX(0, i).longValue()));
        }
    }

    private JDBCXYDataset createDataset() {
        try {
            Connection conn = DriverManager.getConnection(
                "jdbc:h2:mem:test", "", "");
            Statement st = conn.createStatement();
            st.execute("create table inventory(when date, n1 integer, n2 integer)");
            PreparedStatement ps = conn.prepareStatement(
                "insert into inventory values (?, ?, ?)");
            Calendar c = Calendar.getInstance();
            for (int i = 0; i < N; i++) {
                ps.setDate(1, new Date(c.getTimeInMillis()));
                ps.setInt(2, N / 3 + r.nextInt(N / 3));
                ps.setInt(3, N / 2 + r.nextInt(N / 3));
                ps.execute();
                c.add(Calendar.MONTH, 1);
            }
            JDBCXYDataset jds = new JDBCXYDataset(conn);
            jds.executeQuery("select when, n1, n2 from inventory");
            return jds;
        } catch (SQLException ex) {
            ex.printStackTrace(System.err);
        }
        return null;
    }

    public static void main(String[] args) {
        EventQueue.invokeLater(new Runnable() {
            @Override
            public void run() {
                new JDBCTest().display();
            }
        });
    }
}