title: JMenuBar not showing
body: <p>I seem to have done everything correct. I just need to implement a simple <code>JMenuBar</code> but it seems to be not working. Can someone please help me out in this?</p>
  
  <pre><code>import java.awt.*;
  import java.awt.event.*;
  import javax.swing.*;
  import javax.swing.JMenu;
  import javax.swing.JMenuBar;
  import javax.swing.JMenuItem;
  
  public class swing {
     public static void main (String[] args) {
        JFrame frame = new JFrame ("menu");
        frame.setVisible (true);
        frame.setSize (400, 400);
        frame.setDefaultCloseOperation (JFrame.EXIT_ON_CLOSE);
        JMenuBar bar = new JMenuBar ();
        frame.setJMenuBar (bar);
        bar.setVisible (true);
        JMenu file = new JMenu ("File");
        bar.add (file);
        JMenuItem open = new JMenuItem ("open");
        file.add(open);
     }
  }
  </code></pre>