JMenu.setPopupMenuVisible(boolean b) has the following syntax.
public void setPopupMenuVisible(boolean b)
In the following code shows how to use JMenu.setPopupMenuVisible(boolean b) method.
//w w w .jav a 2 s . c o m import javax.swing.JFrame; import javax.swing.JMenu; import javax.swing.JMenuBar; import javax.swing.JMenuItem; public class Main { public static void main(final String args[]) { JFrame frame = new JFrame(); frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); JMenuBar menuBar = new JMenuBar(); // File Menu, F - Mnemonic JMenu fileMenu = new JMenu("File"); // File->New, N - Mnemonic JMenuItem newMenuItem = new JMenuItem("New"); fileMenu.add(newMenuItem); frame.setJMenuBar(menuBar); frame.setSize(350, 250); frame.setVisible(true); fileMenu.setPopupMenuVisible(true); } }