Simple Java fetching MySQL records into DefaultTableModel

frmGuiFetch.java

class frmGuiFetch {

  public static void main(String[] args) 
  {
    guiFetch f = new guiFetch();
    f.setVisible(true);
  }
}

guiFetch.java

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

class guiFetch extends JFrame {  
  Connection cn;
  Statement stmt;

  DefaultTableModel model = new DefaultTableModel();
  JTable table = new JTable(model);
  private JButton btnTutup = new JButton("Tutup");
  private JButton btnProses = new JButton("Proses");

  public guiFetch(){
    setTitle("Table Grid");
    setSize(350,300);
    setLocation(new Point(250,250));
    setLayout(null);    
    setResizable(false);

    JScrollPane scroll = new JScrollPane(table);
    scroll.setBounds(20,60,320,200);
    btnTutup.setBounds(20,20,100,20);
    btnProses.setBounds(200,20,100,20);

    add(btnTutup);
    add(btnProses);
    add(scroll);
    
    model.addColumn("X");
    model.addColumn("Y");
    model.addColumn("Z");

    initDb();
    initTable();
    event();
  }

  public void initDb(){
    try {            
      Class.forName("com.mysql.jdbc.Driver");
      cn = DriverManager.getConnection ("jdbc:mysql://localhost:3306/test", 
                                        "root", 
                                        "toor");        
      stmt = cn.createStatement();      
    } catch (Exception ex) {
      System.err.println(ex);
    }
  }

  public void initTable(){   
    try {  
      while (model.getRowCount()>0){
        model.removeRow(0);
      }
      ResultSet rs = stmt.executeQuery("SELECT * FROM test");
      while(rs.next()){
        model.addRow(new Object[]{
          rs.getString("x"),
          rs.getString("y"),
          rs.getString("z")});
      } 
    }catch (Exception ex) {
      System.err.println(ex);
    }
  }

  private void event(){
		this.addWindowListener(new WindowAdapter() {
			public void windowClosing(WindowEvent e){
        try{
          cn.close();
        }catch (Exception ex) {
          System.err.println(ex);
        }
        
			  System.exit(1);
			}
		});

    btnTutup.addActionListener(new ActionListener() {
			public void actionPerformed(ActionEvent e) {
			  btnTutupClick(e);
			}
		});

    btnProses.addActionListener(new ActionListener() {
			public void actionPerformed(ActionEvent e) {
			  btnProsesClick(e);
			}
		});
  }

  private void btnTutupClick(ActionEvent evt){
    System.exit(1);
  }

  private void btnProsesClick(ActionEvent evt){
    try{
      String sql;

      sql = "INSERT INTO test VALUES (0,'X',CURRENT_TIMESTAMP)";
      stmt.execute(sql);

      initTable();

    }catch (Exception ex) {
      System.err.println(ex);
    }
  }
}

test-ddl.sql

-- sample test table

CREATE TABLE `test` (
  `x` int(11) NOT NULL AUTO_INCREMENT,
  `y` varchar(10) DEFAULT NULL,
  `z` datetime DEFAULT NULL,
  PRIMARY KEY (`x`)
)