membuat konversi

2. import java.awt.*;
import java.awt.event.*;
import javax.swing.*;

public class b extends JFrame {
JLabel l1 = new JLabel("Celcius");
JLabel l2 = new JLabel("Fahreinheit");
JTextField tf1 = new JTextField();
JTextField tf2 = new JTextField();
JPanel p1 = new JPanel();
JButton bKonvert = new JButton("Konvert");
JButton bHapus = new JButton("Hapus");
public b() {
super ("Konversi");
setSize(200,250);
p1.setLayout(null);
setDefaultCloseOperation(EXIT_ON_CLOSE);
setLocationRelativeTo(null);
setResizable(false);

l1.setBounds(75,5,100,25);
tf1.setBounds(50,30,100,25);
l2.setBounds(68,55,100,25);
tf2.setBounds(50,80,100,25);
bKonvert.setBounds(10,135,80,25);
bHapus.setBounds(105,135,80,25);
p1.add(l1);
p1.add(tf1);
p1.add(l2);
p1.add(tf2);
p1.add(bKonvert);
p1.add(bHapus);
getContentPane().add(p1);

tf2.setEditable(false);
bHapus.setEnabled(false);
bKonvert.addActionListener(new ActionListener() {
public void actionPerformed (ActionEvent ae) {
if(ae.getSource() == bKonvert) {
bHapus.setEnabled(true);
double angka = Double.parseDouble(tf1.getText());
double hasil = angka*1.8+32;
tf2.setText(Double.toString(hasil));
}
}
});
bHapus.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent ae) {
tf1.setText("");
tf2.setText("");
}
});

setVisible(true);
}
public static void main(String []xxx) {
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName() );
new b();
}
catch (Exception e) {
}
}
}