Find Intersection of Two BST

Intersection.java

class TreeNode {
    int val;
    TreeNode left;
    TreeNode right;

    public TreeNode(int x) { this.val = x; }
}

public void printIntersection(TreeNode p, TreeNode q) {
    if (p == null || q == null) {
        return;
    }

    if (p.val < q.val) {
        printIntersection(p, q.left);
        printIntersection(p.right, q);
    } else if (p.val > q.val) {
        printIntersection(p.left, q);
        printIntersection(p, q.right);
    } else {
        System.out.println("find " + p.val);
        printIntersection(p.left, q.left);
        printIntersection(p.right, q.right);
    }
}