Exception in thread "main" java.lang.NullPointerException

[Andrew Sepulveda]

the user interface class

package scared;

import java.awt.FlowLayout;
import java.awt.event.ItemEvent;
import java.awt.event.ItemListener;

import javax.swing.*;

	class failure extends JFrame{
		
	
		private JComboBox item;
		private JLabel pictures;
		
		private static String[] files = {"hq insurance.png","insurance building.png"};
		private Icon[] pics = {new ImageIcon(getClass().getResource(files[0]))};

		public failure(){
			super("insurance");
			setLayout(new FlowLayout());
			
			item.addItemListener(
					new ItemListener(){
						public void itemStateChanged(ItemEvent event){
							if(event.getStateChange()==ItemEvent.SELECTED);
							pictures.setIcon(pics[item.getSelectedIndex()]);
				}
			}
		);
			add(item);
			pictures=new JLabel(pics[0]);
			add(pictures);
	}
}

the main class

package scared;

import javax.swing.JFrame;

 class gui {

	public static void main (String[] args){
		
		failure gui = new failure();
		gui.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		gui.setSize(500,200);
		gui.setVisible(true);
	}
}

I am not sure why I am getting this...

Exception in thread "main" java.lang.NullPointerException
	at scared.failure.<init>(failure.java:22)
	at scared.gui.main(gui.java:9)

I am running on eclipse and it does not show in the code itself that it is an error, only in the console.
Anybody realize why this is happening?

[Ralph Cook]

One of the great things about Java is that the error messages usually give you a good idea of what's going on; just read them carefully.

In your case it says "NullPointerException", and "failure.java:22", meaning line 22 in that class.

line 22 contains "item.addItemListener..."; you should be wondering if item has been instantiated.

And you can look back and see that, although you declared item to be a JComboBox, you never instantiated a JComboBox to put in it.

rc

[Andrew Sepulveda]

thank you. the program now works functionally.