LeetCode Convert Sorted List to Binary Search Tree

Given a singly linked list where elements are sorted in ascending order, convert it to a height balanced BST.

/**
 * Definition for singly-linked list.
 * public class ListNode {
 *     int val;
 *     ListNode next;
 *     ListNode(int x) { val = x; next = null; }
 * }
 */
/**
 * Definition for binary tree
 * public class TreeNode {
 *     int val;
 *     TreeNode left;
 *     TreeNode right;
 *     TreeNode(int x) { val = x; }
 * }
 */
public class Solution {
    public TreeNode sortedListToBST(ListNode head) {
        ArrayList<ListNode> listNodes=new ArrayList<ListNode>();
        if (head==null) return null;
        ListNode node=head;
        while (node!=null) {
            listNodes.add(node);
            node=node.next;
        }
        int middle=(listNodes.size()-1)/2;
        TreeNode root =new TreeNode(listNodes.get(middle).val);
        if (middle>0){
            listNodes.get(middle-1).next=null;
            root.left=sortedListToBST(listNodes.get(0));

        }
        if (middle<listNodes.size()-1){
            root.right=sortedListToBST(listNodes.get(middle+1));

        }
        return root;

    }
}