Casting an object to a generic (or storing inner class variable as generic)

Question

I'm getting a warning when I try to cast to a generic type from an Object. Since my underlying data structure on my inner Node class is an array, I can't make Node generic since I can't create generic arrays, and thus my val parameter has to be an Object.

is there any work around or a better way of doing this? I could just suppress warnings but I'm not sure if that's going to have ramifications I should be concerned about.

I'm also making different trees that implement the MyTreeI and will all have different Node structures (so I can't just make an actual Node class (would that even work? I don't know.. maybe))

Ex code here:

public class MyTree<E> implements MyTreeI<E> {
    private Node root;      // root of tree


    private static class Node {
        private Object val;
        private Node[] children = new Node[2];
    }

    public MyTree() {
    }


    @Override
    public E get(String key) {
        Node x = getNode(key); // helper function, assume it returns node in question
        return (E) x.val;
    }
}

Answer 1

I can't make Node generic since I can't create generic arrays

Making Node generic doesn't inhibit you from using arrays of Node . You can't create new Node<E>[...] , true; but you can create new Node<?>[...] or new Node[...] and cast it to Node<E>[] , or just change the type of children to Node<?>[] . There are many possible ways to do this.

public class MyTree<E> implements MyTreeI<E> {
    private Node<E> root;      // root of tree


    private static class Node<E> {
        private E val;
        private Node<E>[] children = (Node<E>[])new Node<?>[2];
    }

    public MyTree() {
    }


    @Override
    public E get(String key) {
        Node<E> x = getNode(key); // helper function, assume it returns node in question
        return x.val;
    }
}