ActionListener

public class Hauptklasse extends JFrame implements ActionListener {
	
  private final String BN1 = "bn1";

	
  private void setGUI() {
    JButton button1 = new JButton("Klick mich1");
    button1.setFont( new Font("Verdana", Font.PLAIN,18));
    // panelBn.add(button1);

    button1.addActionListener(this);
    button1.setActionCommand( BN1  );
  } // setGUI
	
	
  @Override
  public void actionPerformed(ActionEvent e) {
     String cmd = e.getActionCommand();
     switch (cmd) {
       case BN1:
         button1_Click();
         break;
       default:
          editor.append("\nError in actionPerformed: falsches CMD "+cmd );	
     } // switch
   }
	
   private void button1_Click() {
    syso("in button1_click");
   }

}