Stuff

Exception in thread "main" java.lang.NullPointerException
        at ticTacToe.GameBinaryTree.insert(GameBinaryTree.java:36)
        at Test.main(Test.java:15)

public class GameBinaryTree{
                                                                                
        public static final int TO_ROOT =0;
        public static final int TO_LEFT =1;
        public static final int TO_RIGHT=2;
                                                                                
        private TreeNode    root;               //of tree
        private TreeNode current;               //position in tree
        private int         size;               //of tree
                                                                                
        private TreeNode tempNode;
                                                                                
        public GameBinaryTree(){                //default constructor
                root    = null;                 //korrekte manier?
                current = null;                 //ditto
                size    = 0;
        }

public void insert(Object element, int position){
                TreeNode newTreeNode = new TreeNode(element);
                if (position == 0)
                {
                        if (root == null)
                                this.root = newTreeNode;
                }
                else if (position == 1)
                        current.setLeft(newTreeNode);
                else if (position == 2)
                        current.setRight(newTreeNode);
        }

//Inner class that implements a node in the tree.  Each node has elemente of type Object, left and right children, and a parent pointer
        public class TreeNode{
                private Object  element;
                private TreeNode   left;
                private TreeNode  right;
                private TreeNode parent;
                                                                                
                //default constructor - set the element to paramater 'element' and other fields to null
                public TreeNode(Object element){
                this.element = element;
                left         = null;
                right        = null;
                //parent       = null;  //reg om parent na null te sit?
                }

//set left child node element
                public void setLeft(TreeNode to_left){
                        left = to_left;
                }
}

public class Test
{
        private GameBinaryTree$TreeNode node;
                                                                                
        public Test(){
        }
                                                                                
        public static void main(String args[])
        {
        GameBinaryTree gameBT = new GameBinaryTree();
        Test tst = new Test();
        gameBT.insert(new Integer(args[0]),0);
        gameBT.insert("1",1);
        gameBT.insert(new Integer(args[2]),2);
        tst.node = gameBT.getCurrentNode();
        gameBT.insert(new Integer(args[3]),1);
        gameBT.insert(new Integer(args[4]),1);
        gameBT.insert(new Integer(args[5]),1);
        // gameBT.printFromRoot();
        System.out.println(gameBT.getCurrentNodeElement());
        System.out.println(gameBT.getNodeElement(tst.node));
        }
}