java - JMenuBar does not appear in JFrame -

solved forgot instantiate menubar...

i have extended class jmenubar, , class jframe. however, when setjmenubar(menubar), menubar not appear in frame when testing.

here's code:
class frame:

import javax.swing.jframe;  public class frame extends jframe{  public static menubar menubar;  public frame(){     settitle("lol teamcomps");     setlocationrelativeto(null);     setdefaultcloseoperation(exit_on_close);     setjmenubar(menubar);  }     } 

class menubar:

import javax.swing.jmenubar; import javax.swing.jmenuitem; import com.lolteamcomps.code.components.menuitem;  public class menubar extends jmenubar{  public menubar(){     jmenuitem players = new jmenuitem("players");     jmenuitem champions = new jmenuitem("champions");     jmenuitem newplayer = new jmenuitem("add new");     jmenuitem newchampion = new jmenuitem("add new");      players.add(newplayer);     champions.add(newchampion);      add(players);     add(champions);   }  } 

and in function called in main:

private static frame frame = new frame();   public static void createwindow(){     frame.pack();     frame.setvisible(true);    } 

only empty frame appears, nothing in it. doing wrong?

edit: own thought setjmenubar(menubar) won't work, because menubar not jmenubar, menubar extends jmenubar, in fact jmenubar, right? also, don't error @ line, don't think case. thought.

you need instantiate menubar

public  menubar menubar=new menubar();  public frame(){  ....  setjmenubar(menubar); }