Isi JFreechart TimeSeriesCollection dari Mysql DB?

Saya menduga Anda kehilangan presisi dalam konversi String ke Date . Contoh lengkap ini membuat tabel database yang sesuai di memori, menanyakannya ke JDBCXYDataset dan menampilkan kumpulan data dalam bagan deret waktu. Perhatikan bahwa JDBCXYDataset mengenali data deret waktu. Sebagai tanda centang, JDBCXYDataset ditanyai untuk nilai tanggal yang dikembalikan.

Data per jam biasa:

…
Jul 15, 2014 1:10:25 PM
Jul 15, 2014 2:10:25 PM
Jul 15, 2014 3:10:25 PM
Jul 15, 2014 4:10:25 PM
Jul 15, 2014 5:10:25 PM
Jul 15, 2014 6:10:25 PM
…

Kode:

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.sql.Timestamp;
import java.text.DateFormat;
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.data.jdbc.JDBCXYDataset;

/**
 * @see http://stackoverflow.com/a/24762078/230513
 */
public class JDBCTest {

    private static final int N = 24;
    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.createTimeSeriesChart(
            "Inventory", "Date", "Count", jds, true, true, false);
        f.add(new ChartPanel(chart));
        f.pack();
        f.setLocationRelativeTo(null);
        f.setVisible(true);
        for (int i = 0; i < jds.getItemCount(); i++) {
            System.out.println(DateFormat.getDateTimeInstance()
                .format(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 timestamp, n1 integer, n2 integer)");
            PreparedStatement ps = conn.prepareStatement(
                "insert into inventory values (?, ?, ?)");
            Calendar c = Calendar.getInstance();
            for (int i = 0; i < N; i++) {
                ps.setTimestamp(1, new Timestamp(c.getTimeInMillis()));
                ps.setInt(2, N / 3 + r.nextInt(N / 2));
                ps.setInt(3, N / 2 + r.nextInt(N / 2));
                ps.execute();
                c.add(Calendar.HOUR_OF_DAY, 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();
            }
        });
    }
}