First of all, we have to create a JFrame window which acts as container for all components. Then we have to add JMenuBar in it. The JMenuBar will contain JMenus and each JMenu will contain JMenuItems. During actual coding we go in reverse order. First we create JMenuItems. We give a label to it and add ActionListener to it. ActionListener is the way of saying JVM (Java Virtual Machine) which method to execute when the user clicks the particular JMenuItem. After that, we create JMenus and add those created JMenuItems in required JMenus. Then after, we create JMenuBar and add those JMenus in it in required order. Finally, we attach the JMenuBar to the JFrame. To demonstrate all these, I have created two java files -  AppMenuBar.java and JMenuTest.java. The Full source code with descriptive comments can be downloaded here. – Source Code.

Sample code

To create JMenuItem.

JMenuItem item = new JMenuItem(“Show All Empty Seats”);

item.addActionListener(this);

This creates a menu item with label ‘Show All Empty Seats’ and adds itself (the object which is calling the statement—the object of class AppMenuBar).

JMenu showMenu =  new JMenu(“Show”);

showMenu.add(item);

These above statements create a JMenu with label ‘Show’ and add a JMenuItem created above.

The signature of actionPerformed() method in class which implements the ActionListener Interface should be like this.

public void actionPerformed(ActionEvent e) {

            if(e.getActionCommand()==“Reserve a Seat”){

                  jMenuTest.showMessage(“A Seat Reserved”);            

            }

}

Finally, the JMenus created above can be added to JMenuBar like below.

JMenuBar menubar = new  JMenuBar();

menubar.add(showMenu);

The menubar created above can be set as JMenuBar of the JFrame as below.

setJMenuBar(menubar);

In the source code attached, AppMenuBar.java creates a JMenuBar with a JMenu named ‘Show’ with 2 JMenuItems and another JMenu named ‘Transaction’ with 4 JMenuItems. AppMenuBar class inherits built-In class JMenuBar. It also implements ActionListener Interface class. That’s why, it has got actionPerformed() method. Any class which implemensts ActionListener Interface can be action listener of the JMenuItem and those classes will have actionPerformed() method. I have used this actionPerformed() method to change the Message label text of the calling JFrame.

JMenuTest class inherits the built-in classs JFrame. In constructor method, it creates an AppMenuBar and sets that as its JMenuBar. Also, it creates a JLabel and adds that to it. I have not use any layout format so far, so the JLabel is added to middle covering the entire JFrame container. I will discuss more on the Layouts in forth coming posts. The final output picture is shown below.

JMenu Test Sample Picture