โปรแกรมรับค่าจาก TextField แล้วแสดง output อย่างง่าย

[src]import java.awt.*;
import javax.swing.*;
import java.awt.event.*;

class art3 {
private static String output;
private static int sum=0;

public static void main(String args[]){

JFrame main=new JFrame("TEST");
JButton b=new JButton("Calulate");
final JTextField input=new JTextField("0");
// Do calulation below

sum=10;
//end calculation


b.addActionListener(new ActionListener()
{
public void actionPerformed(ActionEvent arg0) {
int a;
a=Integer.parseInt(input.getText());
output=String.valueOf(sum+a);
JOptionPane.showMessageDialog(null,output);

}

});
main.getContentPane().add(input,BorderLayout.NORTH);
main.getContentPane().add(b,BorderLayout.SOUTH);
main.setSize(200,200);
main.show();

}

}
[/src]