Migrar para applet

import javax.swing.JApplet;
import javax.swing.JButton;
import javax.swing.JFrame;

public class Teste extends JApplet {
    @Override
    public void init() {
        JButton btnBotao = new JButton("Clica Aqui!");

        JFrame frame = new JFrame("Oie");
        frame.add(btnBotao);

        this.add(frame.getContentPane());
    }
}