Java中的泛型二进制搜索树实现-调用泛型方法和强制转换异常

public class BinarySearchTree<T extends Comparable<T>> {
    private Node<T> root;

    private class Node<T> {
        private T data;
        private Node<T> left;
        private Node<T> right;

        public Node(T data) {
            this.data = data;
            this.left = null;
            this.right = null;
        }
    }

    public void insert(T data) {
        root = insert(root, data);
    }

    private Node<T> insert(Node<T> node, T data) {
        if (node == null) {
            return new Node<>(data);
        }

        if (data.compareTo(node.data) < 0) {
            node.left = insert(node.left, data);
        } else if (data.compareTo(node.data) > 0) {
            node.right = insert(node.right, data);
        }

        return node;
    }

    public boolean search(T data) {
        return search(root, data);
    }

    private boolean search(Node<T> node, T data) {
        if (node == null) {
            return false;
        }

        if (data.compareTo(node.data) == 0) {
            return true;
        } else if (data.compareTo(node.data) < 0) {
            return search(node.left, data);
        } else {
            return search(node.right, data);
        }
    }

    public void delete(T data) {
        root = delete(root, data);
    }

    private Node<T> delete(Node<T> node, T data) {
        if (node == null) {
            return null;
        }

        if (data.compareTo(node.data) < 0) {
            node.left = delete(node.left, data);
        } else if (data.compareTo(node.data) > 0) {
            node.right = delete(node.right, data);
        } else {
            if (node.left == null) {
                return node.right;
            } else if (node.right == null) {
                return node.left;
            }

            node.data = findMin(node.right);
            node.right = delete(node.right, node.data);
        }

        return node;
    }

    private T findMin(Node<T> node) {
        while (node.left != null) {
            node = node.left;
        }
        return node.data;
    }
}