Submenu Example

import java.awt.EventQueue;
import java.awt.event.ActionEvent;
import javax.swing.ImageIcon;
import javax.swing.JFrame;
import javax.swing.JMenu;
import javax.swing.JMenuBar;
import javax.swing.JMenuItem;

public class SubmenuEx extends JFrame {

    public SubmenuEx() {

        initUI();
    }

    private void initUI() {

        createMenuBar();

        setTitle("Submenu");
        setSize(360, 250);
        setLocationRelativeTo(null);
        setDefaultCloseOperation(EXIT_ON_CLOSE);
    }

    private void createMenuBar() {

        JMenuBar menubar = new JMenuBar();

        ImageIcon iconNew = new ImageIcon("new.png");
        ImageIcon iconOpen = new ImageIcon("open.png");
        ImageIcon iconSave = new ImageIcon("save.png");
        ImageIcon iconExit = new ImageIcon("exit.png");

        JMenu fileMenu = new JMenu("File");

        JMenu impMenu = new JMenu("Import");

        JMenuItem newsfMi = new JMenuItem("Import newsfeed list...");
        JMenuItem bookmMi = new JMenuItem("Import bookmarks...");
        JMenuItem mailMi = new JMenuItem("Import mail...");

        impMenu.add(newsfMi);
        impMenu.add(bookmMi);
        impMenu.add(mailMi);

        JMenuItem newMi = new JMenuItem("New", iconNew);
        JMenuItem openMi = new JMenuItem("Open", iconOpen);
        JMenuItem saveMi = new JMenuItem("Save", iconSave);

        JMenuItem exitMi = new JMenuItem("Exit", iconExit);
        exitMi.setToolTipText("Exit application");

        exitMi.addActionListener((ActionEvent event) -> {
            System.exit(0);
        });

        fileMenu.add(newMi);
        fileMenu.add(openMi);
        fileMenu.add(saveMi);
        fileMenu.addSeparator();
        fileMenu.add(impMenu);
        fileMenu.addSeparator();
        fileMenu.add(exitMi);

        menubar.add(fileMenu);

        setJMenuBar(menubar);
    }

    public static void main(String[] args) {

        EventQueue.invokeLater(() -> {
            SubmenuEx ex = new SubmenuEx();
            ex.setVisible(true);
        });
    }
}

JPopupMenu Example

import java.awt.*;
import java.awt.event.*;

import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JMenuItem;
import javax.swing.JPanel;
import javax.swing.JPopupMenu;

public class SwingJpopupMenu{
   private JFrame mainFrame;
   private JLabel headerLabel;
   private JLabel statusLabel;
   private JPanel controlPanel;

   public SwingJpopupMenu(){
      prepareGUI();
   }
   public static void main(String[] args){
      SwingJpopupMenu  swingMenuDemo = new SwingJpopupMenu();    
      swingMenuDemo.showPopupMenuDemo();
   }
   private void prepareGUI(){
      mainFrame = new JFrame("Java SWING Examples");
      mainFrame.setSize(400,400);
      mainFrame.setLayout(new GridLayout(3, 1));

      headerLabel = new JLabel("",JLabel.CENTER );
      statusLabel = new JLabel("",JLabel.CENTER);       
      statusLabel.setSize(350,100);
     
      mainFrame.addWindowListener(new WindowAdapter() {
         public void windowClosing(WindowEvent windowEvent){
            System.exit(0);
         }       
      });
      controlPanel = new JPanel();
      controlPanel.setLayout(new FlowLayout());

      mainFrame.add(headerLabel);
      mainFrame.add(controlPanel);
      mainFrame.add(statusLabel);
      mainFrame.setVisible(true); 
   }
   private void showPopupMenuDemo(){
      final JPopupMenu editMenu = new JPopupMenu("Edit");

      JMenuItem cutMenuItem = new JMenuItem("Cut");
      cutMenuItem.setActionCommand("Cut");

      JMenuItem copyMenuItem = new JMenuItem("Copy");
      copyMenuItem.setActionCommand("Copy");

      JMenuItem pasteMenuItem = new JMenuItem("Paste");
      pasteMenuItem.setActionCommand("Paste");

      MenuItemListener menuItemListener = new MenuItemListener();

      cutMenuItem.addActionListener(menuItemListener);
      copyMenuItem.addActionListener(menuItemListener);
      pasteMenuItem.addActionListener(menuItemListener);

      editMenu.add(cutMenuItem);
      editMenu.add(copyMenuItem);
      editMenu.add(pasteMenuItem);  

      mainFrame.addMouseListener(new MouseAdapter() {
         public void mouseClicked(MouseEvent e) {           
            editMenu.show(mainFrame, e.getX(), e.getY());
         }              
      });
      mainFrame.add(editMenu);
      mainFrame.setVisible(true);
   }
   class MenuItemListener implements ActionListener {
      public void actionPerformed(ActionEvent e) {           
         statusLabel.setText(e.getActionCommand() + " MenuItem clicked.");
      }   
   }  
}