public static boolean addSeparatorIfNeeded(JPopupMenu popupMenu){
  final int menuComponentCount=popupMenu.getComponentCount();
  if (menuComponentCount == 0) {
    return false;
  }
  final Component lastMenuComponent=popupMenu.getComponent(menuComponentCount - 1);
  if (isPopupMenuSeparator(lastMenuComponent)) {
    return false;
  }
  popupMenu.addSeparator();
  return true;
}

public static boolean addSeparatorIfNeeded ( JPopupMenu popupMenu ) { final int menuComponentCount = popupMenu . getComponentCount ( ) ; if ( menuComponentCount == 0 ) { return false ; } final Component lastMenuComponent = popupMenu . getComponent ( menuComponentCount - 1 ) ; if ( isPopupMenuSeparator ( lastMenuComponent ) ) { return false ; } popupMenu . addSeparator ( ) ; return true ; }
appends a separator to the end of the menu if it exists at least one non separator menu component immediately before and if there isn ' t , already , a separator at the end of the menu .
