Here is a java swing code that updates the jtable automatically after some interval of time.

import java.sql.*;
import java.util.*;
import javax.swing.*;
import javax.swing.table.*; 

public class UpdateJTable extends TimerTask {
    private static JTable table = new JTable(); 
    private static Vector columnNames = new Vector();
    private static Vector data = new Vector();
    private static JFrame f = new JFrame();
    private static JScrollPane scrollPane = new JScrollPane();
    public static void main(String[] args) {
        java.util.Timer timer = new java.util.Timer();
        timer.schedule(new UpdateJTable(), 0, 10000);
        } public void run() {
            remove();
            table = draw(); 
            scrollPane.getViewport().add(table, 0); 
            f.getContentPane().add(scrollPane);
            f.setVisible(true);
            f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); 
            f.pack(); 
            } public static JTable draw() {
                try { Class.forName("com.mysql.jdbc.Driver").newInstance(); 
                Connection con = DriverManager.getConnection( "jdbc:mysql://localhost/test", "root", "root");
                String sql = "Select * from employee"; 
                Statement stmt = con.createStatement(); 
                ResultSet rs = stmt.executeQuery(sql); 
                ResultSetMetaData md = rs.getMetaData(); 
                int columns = md.getColumnCount(); 
                for (int i = 1; i <= columns; i++) {
                    columnNames.addElement(md.getColumnName(i)); }
                    while (rs.next()) {
                        Vector row = new Vector(columns);
                        for (int i = 1; i <= columns; i++) { 
                            row.addElement(rs.getObject(i)); 
                            } data.addElement(row);
                            } rs.close();
                            stmt.close();
                            } 
                            catch (Exception e) {
                                System.out.println(e); 
                                e.printStackTrace(); 
                                } 
                                table.setModel(new DefaultTableModel(data, columnNames));
                                TableColumn col;
                                table.setAutoResizeMode(JTable.AUTO_RESIZE_OFF);
                                for (int i = 0; i < table.getColumnCount(); i++) {
                                    col = table.getColumnModel().getColumn(i);
                                    col.setMaxWidth(col.getMaxWidth());
                                    } return table;
                                    }
                                    public static void remove() {
                                        columnNames.clear();
                                        if (table.getRowCount() != 0) {
                                            DefaultTableModel dm = (DefaultTableModel) table.getModel();
                                            dm.getDataVector().removeAllElements(); 
                                            }
                                            }
                                            }