import javax.swing.JButton;

public class fenster extends javax.swing.JFrame
{
   public fenster()
   {
      this.getContentPane().setLayout(null);
      meinButton = new JButton("Hallo");
      meinButton.setBounds(60,60,80,24);
      this.getContentPane().add(meinButton);
   }

   JButton meinButton;

   public static void main(String[] args)
   {
      fenster meinFenster = new fenster();
      meinFenster.setSize(320, 200);
      meinFenster.setVisible(true);
   }
}