Adding a JMenuBar

Question

I am trying to create a simple JMenuBar in the application enlosed below.
I keep getting the following error when ever i compile
"Screen.java": Error #: 300 : method setJMenuBar(javax.swing.JMenuBar) not found in class random.Screen at line 67, column 9". Can some one please enlighten me.
Class Screen is the main class. This is where the GUI is set up. it calls class Canvas which in turn calls class Nodes. GUI draws a bus network which holds a minimum of two nodes and a maximum of 10. The node number is under user control. The aim is to allow a user to select the configure menu to update the number of nodes on display in the GUI.
package random;
import javax.swing.JPanel;
import javax.swing.border.*;
import java.awt.*;
import javax.swing.*;
import javax.swing.border.*;
import java.awt.event.*;
* <p>Title: Simulation of the random load balancing algorithm </p
public class Screen extends JPanel {
static int screenWidth = (int)(Toolkit.getDefaultToolkit().getScreenSize().width*0.85);
static int screenHeight = (int)(Toolkit.getDefaultToolkit().getScreenSize().height*0.95);
private Container container;
JButton add;
Canvas canvas;
JMenuBar menubar;
JMenu configure;
Thread animatorThread;
RandomApplet RApplet;
public Screen(RandomApplet RApplet){
     this.RApplet = RApplet;
     makeGui();
public Screen(){
     makeGui();
public void makeGui(){
addMenu();
GridBagLayout gridbag = new GridBagLayout();
     setLayout(gridbag);
     GridBagConstraints c = new GridBagConstraints();
     c.insets = new Insets(1,1,1,1);
     //add drawing canvas
     canvas = new Canvas();
     c.gridx = 0;
     c.gridy = 0;
     c.weightx=1.0;
     c.weighty=1.0;
     c.fill=GridBagConstraints.BOTH;
     gridbag.setConstraints(canvas, c);
     add(canvas);
     c.gridx=0;
     c.gridy=1;
     gridbag.setConstraints(canvas,c);
     add(add=addButton("Add"));
private void addMenu(){
     menubar = new JMenuBar();
setJMenuBar(menubar);
     configure = new JMenu("Configure");
     configure.add(new JMenuItem("add"));
     menubar.add(configure);
private JButton addButton(String name) {
          JButton b = new JButton(name);
          ButtonHandler handler=new ButtonHandler();
          b.addActionListener(handler);
          b.setFont(new Font("Dialog", Font.BOLD, 12));
          b.setMargin(new Insets(0,0,0,0));
          return b;
class ButtonHandler implements ActionListener{
     public void actionPerformed(ActionEvent e){
          if (e.getSource()== add){
               if (canvas.addNode()){
               repaint();
public void run(){
     Thread thisThread = Thread.currentThread();
     while (animatorThread == thisThread){
          try {
          Thread.sleep(100);}
          catch (Exception e){
          break;}
public static void main(String[] args) {
JFrame f=new JFrame("Random");
     f.setSize(screenWidth, screenHeight);
     f.getContentPane().add(new Screen());
     f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
f.setVisible(true);
//class Canvas
package random;
import javax.swing.JPanel;
import java.awt.*;
import java.util.*;
import java.awt.Graphics;
import java.awt.image.*;
import javax.swing.*;
public class Canvas extends JPanel{
int width, height;
Dimension size;
Image canvasImage = null;
Graphics canvasGraphics;
Image networkMem;
int NodeWidth, NodeHeight;
Nodes[] n;
int numberOfNodes;
int x1, y1,x2,y2;
public Canvas(){
// canvas a perfect square
     height = 400;
     width = 400;
     size=new Dimension(width,height);
     setBackground(Color.white);
     networkMem=Toolkit.getDefaultToolkit().createImage("images/computer6.gif");
     NodeWidth = networkMem.getWidth(this);
NodeHeight = networkMem.getHeight(this);
     //network must hold a minimum of 2 nodes
     n = new Nodes[11];
     n[0] = new Nodes(0,this);
     n[1] = new Nodes(1,this);
     numberOfNodes = 2;
public void paintComponent(Graphics g)
super.paintComponent(g);
     //create canvas image
     if (canvasImage==null){
          canvasImage=createImage(getSize().width,getSize().height);
          canvasGraphics = canvasImage.getGraphics();
     //adjust above to fit canvas window
if ((canvasImage.getWidth(this) != getSize().width) || (canvasImage.getHeight(this) != getSize().height)){
     canvasImage = createImage(getSize().width,getSize().height);
          if (canvasImage!=null){
          canvasGraphics.dispose();
          canvasGraphics = canvasImage.getGraphics();
     //create a rectangular border outlining canvas area
     canvasGraphics.drawRect(0,0,getSize().width-1,getSize().height-1);
     x1=width-100;
     y1=height-100;
     x2=width-300;
     y2=width-100;
canvasGraphics.drawLine(x1,y1,x2,y2);
//canvasGraphics.drawLine(width-300,height-100,width-300,height-50);
     //canvasGraphics.drawLine(width-100,height-100,width-100,height-50);
     for(int i=0; i<numberOfNodes; i++){
     n.drawNode(canvasGraphics);
     g.drawImage(canvasImage, 0, 0, this);
     super.paintComponent(canvasGraphics);
public int getNumberOfNodes()
     return numberOfNodes;
public boolean addNode(){
     //add a node to network
     if (numberOfNodes < 10) {
     n[numberOfNodes]= new Nodes(numberOfNodes, this);
     numberOfNodes++;
     repaint();
     return true;
     return false;
public boolean removeNode(){
     boolean removed = false;
     if (numberOfNodes >2) {
     numberOfNodes=numberOfNodes - 1;
     removed = true;
     else{
     removed = false;
     repaint();
     return removed;
//class Nodes
package random;
import javax.swing.JPanel;
import javax.swing.*;
import java.awt.*;
import java.awt.Graphics;
public class Nodes{
int nodeNumber;
Canvas canvas;
public Nodes(int number, Canvas c) {
//each node has a number id
     nodeNumber=number;
     canvas=c;
public void drawNode(Graphics g){
     if (nodeNumber%2 == 0){
canvas.x1=canvas.x1-10;
     System.out.println(""+canvas.x1);
     g.drawLine(canvas.x1,canvas.y1,canvas.x1,canvas.y2-50);
     g.drawImage(canvas.networkMem,canvas.x1,canvas.y1-80,canvas);
     else{
     canvas.x1=canvas.x1-30;
     System.out.println(""+canvas.x1);
     g.drawLine(canvas.x1,canvas.y1,canvas.x1,canvas.y2+50);
     g.drawImage(canvas.networkMem,canvas.x1,canvas.y2+50,canvas);

Answer 1

Thanks for the reply but i figured it out in the end.
I can make use of the following commands
setMenuBar(MenuBar mb)
getMenuBar()
to set the main frame menubar to that declared in addmenu() .
if I add the following code to main() in the screen class the menu appears
Screen screen = new Screen(null);
f.setJMenuBar(screen.getMenuBar());