BST Deletion

remove

/**
 * Removes a data entry from the BST
 * 
 * null is positive infinity
 * 
 * @param data The data entry to be removed
 * @return The removed data entry (null if nothing is removed)
 * 
 */
public T remove(T data) {
	boolean b = false;
	if(contains(data)){
		b = true;
	}
	root = remove(root, data);
	if(b){
		return data;
	}
	return null;
}
private Node<T> remove(Node<T> here, T data) {
	if (here != null) {
		if(data == null){
			here.right = remove(here.right, data);
			if(here.getData() == null){
				here = removeNode(here);
			}
		}else{
			if (data.compareTo(here.getData()) < 0) {
				here.left = remove(here.left, data);
			} else if (data.compareTo(here.getData()) > 0) {
				here.right = remove(here.right, data);
			} else {
				here = removeNode(here);
			}
		}
		
	}
	return here;
}
private Node<T> removeNode(Node<T> here) {
	if (here.left == null)
		here = here.right;
	else if (here.right == null)
		here = here.left;
	else {			
			Node<T> big = here.left;
			Node<T> last = null;
			while (big.right != null) {
				last = big;
				big = big.right;
			}
			here.data = big.data;
			if (last == null) {
				here.left = big.left;
			} else {
				last.right = big.left;
			}
		}	
	return here;
}