import java.awt.event.*;import javax.swing.*;public class MainApp extends JFrame implements ActionListener{ MyFrame frame1 // irgendeine deiner Frameklassen JMenuBar menuBar; JMenu menu1; // ... JMenuItem menuItemFrame1; public MainApp() { // menuBar initialisieren ... hinzufügen der Items, bla bla this.menuItemFrame1.addActionListener(this); // irgendeins deiner Frames this.frame1 = new MyFrame(); } public static void main(String[] argv) { BaseApp baseApp = new BaseApp("..."); baseApp.setJMenuBar(menuBar); baseApp.setLocation(0, 0); baseApp.setSize(800, 600); baseApp.setVisible(true); } public void actionPerformed(ActionEvent e) { if (e.getSource() == this.menuItemFrame1) { this.frame1.doSomething(...); // irgendetwas, was dein frame // machen soll. } }}