じゃヴぁ０８１５ - プログラム倉庫

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

class game0815{
public static void main(String[] args) {
JFrame f = new JFrame();
JButton b1 = new JButton("OK");
f.getContentPane().add(b1);
f.setSize(700,700);
f.setBackground(Color.blue) ;
f.setVisible(true);
f.addWindowListener(new WindowAdapter(){public void
windowClosing(WindowEvent e){System.exit(0);}});
}
}