Kalkulator Ringkas

import java.awt.EventQueue;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.UIManager;
import javax.swing.border.EmptyBorder;
import javax.swing.JTextField;
import java.awt.event.ActionListener;
import java.awt.event.ActionEvent;
import javax.swing.JButton;
import java.awt.Color;
import javax.swing.JLabel;
import javax.swing.ImageIcon;
import javax.swing.SwingConstants;

@SuppressWarnings("serial")
public class Frm extends JFrame {

    private JPanel contentPane;
    private JTextField txt1;
    private JTextField txt2;
    private JTextField txtHasil;
    double hasil;
    private JButton Tambah;
    private JButton Kurang;
    private JButton Kali;
    private JButton Bagi;
    private JButton Refresh;
    private JLabel lblIcon;

    /**
     * Create the frame.
     */
    public Frm() {
        setTitle("Kalkulator Ringkas");
        setResizable(false);
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        setBounds(100, 100, 358, 278);
        contentPane = new JPanel();
        contentPane.setBackground(Color.GRAY);
        contentPane.setBorder(new EmptyBorder(5, 5, 5, 5));
        setContentPane(contentPane);
        contentPane.setLayout(null);

        txt1 = new JTextField();
        txt1.setBounds(12, 25, 233, 28);
        contentPane.add(txt1);
        txt1.setColumns(10);

        txt2 = new JTextField();
        txt2.setColumns(10);
        txt2.setBounds(12, 65, 233, 28);
        contentPane.add(txt2);

        txtHasil = new JTextField();
        txtHasil.setColumns(10);
        txtHasil.setBounds(12, 177, 233, 28);
        contentPane.add(txtHasil);

        Tambah = new JButton("+");
        Tambah.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent arg0) {
                hasil = Double.parseDouble(txt1.getText())
                        + Double.parseDouble(txt2.getText());
                txtHasil.setText("" + hasil);
            }
        });
        Tambah.setBounds(57, 105, 61, 24);
        contentPane.add(Tambah);

        Kurang = new JButton("-");
        Kurang.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent arg0) {
                hasil = Double.parseDouble(txt1.getText())
                        - Double.parseDouble(txt2.getText());
                txtHasil.setText("" + hasil);
            }
        });
        Kurang.setBounds(130, 105, 61, 24);
        contentPane.add(Kurang);

        Kali = new JButton("x");
        Kali.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent arg0) {
                hasil = Double.parseDouble(txt1.getText())
                        * Double.parseDouble(txt2.getText());
                txtHasil.setText("" + hasil);
            }
        });
        Kali.setBounds(57, 141, 61, 24);
        contentPane.add(Kali);

        Bagi = new JButton("/");
        Bagi.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent arg0) {
                hasil = Double.parseDouble(txt1.getText())
                        / Double.parseDouble(txt2.getText());
                txtHasil.setText("" + hasil);
            }
        });
        Bagi.setBounds(130, 141, 61, 24);
        contentPane.add(Bagi);

        Refresh = new JButton("Refresh");
        Refresh.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent arg0) {
                txt1.setText("");
                txt2.setText("");
                txtHasil.setText("");
                txt1.requestFocus();
            }
        });
        Refresh.setBounds(12, 217, 94, 24);
        contentPane.add(Refresh);

        lblIcon = new JLabel("Blankon Linux");
        lblIcon.setHorizontalTextPosition(SwingConstants.CENTER);
        lblIcon.setHorizontalAlignment(SwingConstants.CENTER);
        lblIcon.setVerticalTextPosition(SwingConstants.BOTTOM);
        lblIcon.setForeground(new Color(0, 0, 0));
        lblIcon.setIcon(new ImageIcon(Frm.class
                .getResource("/Kalkulator/64x64.png")));
        lblIcon.setBounds(249, 77, 107, 85);
        contentPane.add(lblIcon);
    }

    /**
     * Launch the application.
     */
    public static void main(String[] args) {
        EventQueue.invokeLater(new Runnable() {
            public void run() {
                try {
                    UIManager.setLookAndFeel(UIManager
                            .getSystemLookAndFeelClassName());
                    Frm frame = new Frm();
                    frame.setVisible(true);
                } catch (Exception e) {
                    e.printStackTrace();
                }
            }
        });
    }
}