java.lang.NullPointerException

[stevemcc]

I am working on a gui application that rolls 5 dice. I have my own separate die and dice classes. I am having trouble making the GUI though. I keep getting a NullPointer.

App.java:

Code:

import javax.swing.JFrame;

public class App {

	public App() {
		// TODO Auto-generated constructor stub
	}

	public static void main(String[] args) {
		JFrame frame = new JFrame ("Push Counter");
	    frame.setDefaultCloseOperation (JFrame.EXIT_ON_CLOSE);
	    frame.getContentPane().add(new AppPanel());

	    frame.pack();
	    frame.setVisible(true);

	}

}

AppPanel.java:

Code:

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;

public class AppPanel extends JPanel {

	private Die die1, die2, die3, die4, die5 = new Die(6);
	private Dice dice = new Dice();
	private JLabel total, d1, d2, d3, d4, d5 = new JLabel("0");
	private JButton rollAll, roll1, roll2, roll3, roll4, roll5 = new JButton("Roll");
	
	public AppPanel() {
		dice.addDie(die1);
		dice.addDie(die2);
		dice.addDie(die3);
		dice.addDie(die4);
		dice.addDie(die5);
		
		//rollAll.addActionListener(new RollAllListener());
		
		add(rollAll);
		add(total);
		
		add(roll1);
		add(d1);
		
		add(roll2);
		add(d2);
		
		add(roll3);
		add(d3);
		add(roll4);
		add(d4);
		add(roll5);
		add(d5);
		
	}

	public static void main(String[] args) {
		// TODO Auto-generated method stub

	}
	
	
	
	
   private class RollAllListener implements ActionListener
   {
      public void actionPerformed (ActionEvent event)
      {
    	  dice.rollAll();
      }
   }

}

Someone else in the class was having the same problem as me, but theres was due to never initializing their buttons and labels. Mine are initialized so I cant figure out why I am getting this error. Can anyone help me out?

[hardwired]

Code:

// die1, die2, die3, die4 are declared and not instantiated
// and so are null.
// die5 = new Die(6) — is not null
private Die die1, die2, die3, die4, die5 = new Die(6);
private Dice dice = new Dice();
// total, d1, d2, d3, d4 are all null, not assigned any value.
// d5 = new JLabel("0") — okay, instantiated.
private JLabel total, d1, d2, d3, d4, d5 = new JLabel("0");
// rollAll, roll1, roll2, roll3, roll4 are all null.
// roll5 = new JButton("Roll") is okay.
private JButton rollAll, roll1, roll2, roll3, roll4, roll5 = new JButton("Roll");

To test/find_out you can try something like:

Code:

public AppPanel() {
    System.out.println("die1 = " + die1);
    dice.addDie(die1);

[stevemcc]

yeah the syntax of some of my instance variables was wrong. This resulted in only the last variable being initialized.