Java - Balance Binary Tree While Inserting Nodes

I am trying to edit a function so that it balances the binary tree as it inserts the new nodes. I cannot use libraries and it must be in raw Java.

The only help given were two sets of instructions:

1)

• How do you rotate a node?

• Node "n" needs to rotate left (it moves to the left and the node on the right replaces it)

• Right's left becomes n's right

• n's right becomes right's left

• n becomes right

LinkedNode r = n.getRight(); // Get the right node

n.setRight(r.getLeft()); // n's right becomes right's left

r.setLeft(n); // right's left becomes n

n = r; // Make n point to r now

• To tell if a node needs to be rotated, you need to know the depth on each side of the node

int ld = depth(n.getLeft());

int rd = depth(n.getRight());

if(ld-rd > 1) // Left is too long - rotate right

if(rd-ld > 1) // Right is too long - rotate left

However no matter how I try to apply these instructions, I can't get the nodes rotated correctly to balance the tree. The original function is as follows:

public void add(T val) {

    LinkedNode<T> t = new LinkedNode<T>(val); // Make a new node
    if (root == null)
        root = t; // Empty tree, so make root the new node

    else {
        // If the root is less than val,
        // Make val the root with the current root on the left
        if (root.get().compareTo(val) < 0) {
            t.setLeft(root);
        }
        // Otherwise, make val the root with the current root on the right
        else {
            t.setRight(root);
        }

        root = t; 
}

Any help is greatly appreciated