Question

I’m trying to build a really basic program that will alternate between two pictures depending on which item from a dropdown box is selected. This is the code I’m trying to run, but I keep getting an error saying:

Exception in thread "main" java.lang.NullPointerException
at javax.swing.ImageIcon.<init>(ImageIcon.java:181)
at Gui.<init>(Gui.java:10)
at Apples.main(Apples.java:7)

The images are in the src file.

Does anyone know what I am doing wrong??
Thanks,
Ravin

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

public class Gui extends JFrame{

private JComboBox box;
private JLabel picture;
private static String [] filename = {"Ravinsface.png", "Wojs face.png"};
private Icon[] pics = {new ImageIcon(getClass().getResource(filename[0])), new      ImageIcon(getClass().getResource(filename[1]))};

public Gui(){
super("The Title");
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);
picture = new JLabel(pics[1]);
add(picture);


}

}

Answer 1

Use getClass().getClassLoader().getResource(String)

/e1 I put an explanation of the different getResource(String) methods on the other answer.