this is the logic for addition of two numbers
public class AddNumbers{
public static void main(String[] args) {
System.out.println("Addition of two numbers!");
int a = Integer.parseInt(args[0]);
int b = Integer.parseInt(args[1]);
int sum = a + b;
System.out.println("Sum: " + sum);
}
}

Hi friend,

import javax.swing.*;
import java.awt.*;
import java.awt.Container;
import java.awt.FlowLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

class AddTwoNumber extends JDialog {
public AddTwoNumber(JFrame parent) {
super(parent, "Add two number", true);
int x = 10;
int y = 20;
int num = x + y;
System.out.println("num:" + num);
Container cp = getContentPane();
cp.setLayout(new FlowLayout());
cp.add(new JLabel("Add two number is: " + num));
JButton ok = new JButton("OK");
ok.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
dispose();
}
});
cp.add(ok);
setSize(300, 150);
}
}

public class AddNumber extends JApplet {
private JButton jb = new JButton("Click Me");

private AddTwoNumber dlg = new AddTwoNumber(null);

public void init(){
jb.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
dlg.show();
}
});
getContentPane().add(jb);
}

public static void main(String[] args) {
Save(new AddNumber(), 300, 200);
}

public static void Save(JApplet applet, int width, int height) {
JFrame frame = new JFrame();
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.getContentPane().add(applet);
frame.setSize(width, height);
applet.init();
applet.start();
frame.setVisible(true);
}
}

---------------------------

Thanks.