Could someone please be kind enough to tell me what I am doing wrong here.
I have been racking my brain for a few days now and I just don't understand
where the problem comes from.

Bassically I have a class that I'm using to keep some static variables in.
The constuctor gets called and the variables are initialized in the right
way. However, when I recall them with my getter, it's as if the get methode
has lost all track of them(the variables), and I get a null pointer assignment
error. Why?

Here Is my storage class:

import javax.swing.JOptionPane;
public class ColumnValues
private static final int MAX_COLS = 4; //
private static int colValue[];
private static int maxValue;

public ColumnValues()
int colValue[] = new int[MAX_COLS];
colValue[0] = 10;
colValue[1] = 20;
colValue[2] = 30;
colValue[3] = 40;
maxValue = 40;
} // default constructor

public static void setColValue(int colNum, int value)
colValue[colNum] = value;
maxValue = ( colValue[colNum] >maxValue ? value : maxValue) ;
} // end of setter

public static int getColValue(int colNum)
return colValue[colNum];
public static int getMaxValue()
return maxValue;

} // end of class columnValues;

Here is the driver:

public class BarDriver
public static void main(String[] args)
ColumnValues cValues = new ColumnValues();

int width, height;
int dummyValue;
dummyValue = ColumnValues.getColValue(1);
JOptionPane.showMessageDialog(null, Integer.toString(dummyValue), "Hi",

+ ...

: The second to the last line gives me null pointer error..

Can some one please help and tell me what I did wrong? Thank you very much..