swing - Menubar not added in a java split pane -

i have written small test program creates split pane in 1 of pane's text area. have added meubar , menuitems pane donot see them in gui created.

could pls point out wrong thing did on here in below program:

import java.awt.*; import java.awt.event.*; import javax.swing.*; import javax.swing.event.*; import javax.swing.jmenubar; import java.util.*; import javax.swing.text.badlocationexception; import java.awt.*; import java.io.ioexception;   //splitpanedemo not visible component. public class splitpanedemo extends jframe                           implements actionlistener {      private jtextarea ta;     private jmenubar menub;         private jmenu dbm;         private jmenuitem cnadb,bsmdb,cdmdb;      private jlabel picture;       private jsplitpane splitpane;     public splitpanedemo() {          ta = new jtextarea(); //textarea         ta.setlinewrap(true);             ta.setwrapstyleword(true);             ta.addkeylistener(new keyadapter()         {                  public void keypressed(keyevent ke )                  {                   int code = ke.getkeycode();                  int modifiers = ke.getmodifiers();                  if(code == keyevent.vk_enter && modifiers == keyevent.ctrl_mask)                  {                   system.out.println("cmd in table:");            }                 }                 });          jscrollpane tapane = new jscrollpane(ta);         picture = new jlabel();         picture.setfont(picture.getfont().derivefont(font.italic));         picture.sethorizontalalignment(jlabel.center);          jscrollpane picturescrollpane = new jscrollpane(picture);          splitpane = new jsplitpane(jsplitpane.vertical_split,                                    tapane, picturescrollpane);         splitpane.setonetouchexpandable(true);         splitpane.setdividerlocation(450);          //provide minimum sizes 2 components in split pane.         dimension minimumsize = new dimension(100, 100);         tapane.setminimumsize(minimumsize);         picturescrollpane.setminimumsize(minimumsize);          //provide preferred size split pane.         splitpane.setpreferredsize(new dimension(900, 900));                menub = new jmenubar(); //menubar         dbm = new jmenu("db"); //file menu             cnadb = new jmenuitem("cna");             bsmdb = new jmenuitem("bsm");             cdmdb = new jmenuitem("cdm");             setjmenubar(menub);             menub.add(dbm);             dbm.add(cnadb);             dbm.add(bsmdb);             dbm.add(cdmdb);             cnadb.addactionlistener(this);             bsmdb.addactionlistener(this);             cdmdb.addactionlistener(this);             setvisible(true);     }         public void actionperformed(actionevent e)          {     }     public void valuechanged(listselectionevent e) {     }      public jsplitpane getsplitpane() {         return splitpane;     }       private static void createandshowgui() {          //create , set window.         jframe frame = new jframe("splitpanedemo");         frame.setdefaultcloseoperation(jframe.exit_on_close);         splitpanedemo splitpanedemo = new splitpanedemo();         frame.getcontentpane().add(splitpanedemo.getsplitpane());          //display window.         frame.pack();         frame.setvisible(true);     }      public static void main(string[] args) {         //schedule job event-dispatching thread:         //creating , showing application's gui.         javax.swing.swingutilities.invokelater(new runnable() {             public void run() {                 createandshowgui();             }         });     }   } 

you add jmenubar in splitpanedemo class, when call createandshowgui, make new jframe , add splitpane call getsplitpane. new frame has no knowledge of menu bar.

if extending jframe in splitpanedemo, why not use make frame gui?