NullPointerException « JComboBox « Java Swing Q&A

  1. Java Swing Q&A
  2. JComboBox
  3. NullPointerException




1. JComboBox is throwing a NullPointerException when told to addItemListener()    stackoverflow.com

I am getting a NullPointerException on line 27 (listOfWindTurbines.addItemListener(new dropDownListener());) when I try to run my program. Please Help! 

import java.awt.event.*;
import java.awt.*;
import javax.swing.*;
public class PlannerMain {
JFrame frame;
JButton makeMap;
JPanel panel;
JLabel outcome;
JComboBox listOfWindTurbines;
String[] windTurbineSpace ...

2. JComboBox: want first entry to be blank entry    stackoverflow.com

I have a jcombobox which values come from a list. I want to first value to be blank from dropdown list. The way I approached it was by putting new object ...