Java Program to Display Sum of Two Numbers using Swings

import javax.swing.*;
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
class Addition extends JFrame implements ActionListener
{
JLabel l1, l2;
JTextField t1, t2, t3;
JButton b1;
public Addition()
{
l1 = new JLabel("Enter the First Number:");
l1.setBounds(20, 10, 100, 20);
t1 = new JTextField(10);
t1.setBounds(120, 10, 100, 20);
l2 = new JLabel("Enter the Second Number:");
l2.setBounds(20, 40, 100, 20);
t2 = new JTextField(10);
t2.setBounds(120, 40, 100, 20);
b1 = new JButton("Sum of Two Numbers:");
b1.setBounds(20, 70, 80, 20);
t3 = new JTextField(10);
t3.setBounds(120, 70, 100, 120);
add(l1);
add(t1);
add(l2);
add(t2);
add(b1);
add(t3);
b1.addActionListener(this);
setSize(400,300);
setLayout(null);
setVisible(true);
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
}
@Override
public void actionPerformed(ActionEvent e)
{
if(e.getSource()==b1){
int n1 = Integer.parseInt(t1.getText());
int n2 = Integer.parseInt(t2.getText());
int sum = n1 + n2;
t3.setText(String.valueOf(sum));
}
public static void main(String args[])
{
new Addition();
}
}