Thread: Java JComboBox and Picture Problem

Hi, I'm learning Java, but I'm getting an Error in my "program" - Please help me fix it.

MY MAIN CLASS:

import javax.swing.JFrame;
 
public class Main {
 
	public static void main(String[] args) {
 
		Gui go = new Gui();
		go.setSize(300, 200);
		go.setVisible(true);
		go.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
 
	}
 
}

MY GUI CLASS:

import java.awt.*;
import java.awt.event.*;
 
import javax.swing.*;
 
public class Gui extends JFrame{
 
	private JComboBox box;
	private JLabel picture;
 
	//The Pictures
	private static String[] filename = {"b.png", "x.png"};
	private Icon[] pics = {new ImageIcon(getClass().getResource(filename[0])), new ImageIcon(getClass().getResource(filename[1]))};
 
	public Gui(){
		super("JComboBox");
		setLayout(new FlowLayout());
 
		box = new JComboBox(filename);
 
		box.addItemListener(
				new ItemListener(){
					public void itemStateChanged(ItemEvent event){
						if(event.getStateChange()==ItemEvent.SELECTED)
							picture.setIcon(pics[box.getSelectedIndex()]);
					}
				}
			);
		add(box);
		//Sets default picture.
		picture=new JLabel(pics[0]);
		add(picture);
 
	}
 
}

NOTE: I have two pictures in my src folder called : "x.png" and "b.png"


IM GETTING THIS ERROR:

Exception in thread "main" java.lang.NullPointerException
	at javax.swing.ImageIcon.<init>(Unknown Source)
	at GUI_JComboBox.Gui.<init>(Gui.java:15)
	at GUI_JComboBox.Main.main(Main.java:9)

Thanks for your time

Use print statements to find the null objects. I'm guessing the files aren't being found so pics[] contains nulls. Start there.