Menu Login dengan Java dan MySQL

Koneksi.java

package programLogin;

import java.sql.Connection;
import java.sql.DriverManager;

public class Koneksi
{
  private static Connection koneksi;
	
	public static Connection getKoneksi()
	{
		if(koneksi==null)
		{
			try
			{
				String url = "jdbc:mysql://localhost/MenuLogin";
				String user = "root";
				String password = "root";
				
				DriverManager.registerDriver(new com.mysql.jdbc.Driver());
				koneksi = DriverManager.getConnection(url,user,password);
			}
			catch(Exception ex)
			{
				System.out.println(ex);
			}
		}
		return koneksi;
	}
}

LoginDatabase.java

package programLogin;
/*
 * @ author resa cr
 */

import java.awt.EventQueue;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.border.EmptyBorder;
import javax.swing.JLabel;
import javax.swing.ImageIcon;
import javax.swing.JButton;
import javax.swing.JOptionPane;
import javax.swing.JTextField;
import javax.swing.JPasswordField;
import javax.swing.UIManager;
import java.awt.Color;
import java.awt.event.ActionListener;
import java.awt.event.ActionEvent;
import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.Statement;

public class LoginDatabase extends JFrame 
{
  private static final long serialVersionUID = 1L;
	private JPanel contentPane;
	private JTextField txtUserName;
	private JPasswordField pf;
	
	public LoginDatabase() 
	{
		setResizable(false);
		setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		setBounds(100, 100, 549, 360);
		contentPane = new JPanel();
		contentPane.setBorder(new EmptyBorder(5, 5, 5, 5));
		setContentPane(contentPane);
		contentPane.setLayout(null);
		setLocationRelativeTo(null);
		
		JLabel lblIcon = new JLabel("");
		lblIcon.setIcon(new ImageIcon("/home/resa/Aplikasi Java/MenuLogin/src/Gambar/Monitor 2.png"));
		lblIcon.setBounds(12, 54, 214, 188);
		contentPane.add(lblIcon);
		
		JButton btnMasuk = new JButton("Masuk");
		btnMasuk.setIcon(new ImageIcon("/home/resa/Aplikasi Java/MenuLogin/src/Gambar/Masuk.png"));
		btnMasuk.addActionListener(new ActionListener() 
		{
			public void actionPerformed(ActionEvent act)
			{
				try
				{
				Connection konek = Koneksi.getKoneksi();
				Statement state = konek.createStatement();
				@SuppressWarnings("deprecation")
				String query = "SELECT * FROM Data WHERE username = '"+txtUserName.getText()+"' and password = '"+pf.getText()+"'";
				
				ResultSet rs = state.executeQuery(query);
				boolean masuk = false;
				masuk = rs.next();
					if(masuk)
					{
						JOptionPane.showMessageDialog(null,"Selamat Datang","Pesan",JOptionPane.INFORMATION_MESSAGE,new ImageIcon("src/Gambar/berhasil.png"));
					}
					else
					{
						JOptionPane.showMessageDialog(null,"Username atau Password salah","Pesan",JOptionPane.ERROR_MESSAGE,new ImageIcon("src/Gambar/error.png"));
						txtUserName.setText(" ");
						pf.setText("");
						txtUserName.requestFocus();
					}
				}
				catch(Exception ex)
				{
					System.out.println(ex);
				}
			}
		});
		btnMasuk.setBounds(249, 243, 117, 42);
		contentPane.add(btnMasuk);
		
		JButton btnBatal = new JButton("Batal");
		btnBatal.setIcon(new ImageIcon("/home/resa/Aplikasi Java/MenuLogin/src/Gambar/Batal.png"));
		btnBatal.addActionListener(new ActionListener() 
		{
			public void actionPerformed(ActionEvent act) 
			{
				JOptionPane.showMessageDialog(null,"Anda keluar dari sistem","Pesan",JOptionPane.INFORMATION_MESSAGE,new ImageIcon("src/Gambar/error.png"));
				dispose();
			}
		});
		btnBatal.setBounds(396, 243, 117, 42);
		contentPane.add(btnBatal);
		
		JLabel lblUsername = new JLabel("Username : ");
		lblUsername.setForeground(new Color(255, 255, 204));
		lblUsername.setBounds(207, 87, 96, 15);
		contentPane.add(lblUsername);
		
		txtUserName = new JTextField();
		txtUserName.setBounds(302, 85, 214, 19);
		contentPane.add(txtUserName);
		txtUserName.setColumns(10);
		
		JLabel lblPassword = new JLabel("Password : ");
		lblPassword.setForeground(new Color(255, 255, 204));
		lblPassword.setBounds(207, 128, 96, 15);
		contentPane.add(lblPassword);
		
		pf = new JPasswordField();
		pf.setBounds(302, 126, 214, 17);
		contentPane.add(pf);
		
		JLabel lblGambar = new JLabel("");
		lblGambar.setForeground(new Color(204, 51, 255));
		lblGambar.setIcon(new ImageIcon("/home/resa/Aplikasi Java/MenuLogin/src/Gambar/biru.jpg"));
		lblGambar.setBounds(0, 0, 545, 333);
		contentPane.add(lblGambar);
	} //Akhir Konstruktor
	
	/**
	 * Launch the application.
	 */
	public static void main(String[] args) 
	{
		EventQueue.invokeLater(new Runnable()
		{
			public void run() {
				try 
				{
					com.jtattoo.plaf.mcwin.McWinLookAndFeel.setTheme("Large-Font", "Menu Login", "");
		            UIManager.setLookAndFeel("com.jtattoo.plaf.mcwin.McWinLookAndFeel");
		            LoginDatabase ld = new LoginDatabase();
					ld.setVisible(true);
				} 
				catch (Exception e) 
				{
					e.printStackTrace();
				}
			}
		});
	}
}