如何在java中重新链接树节点？

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

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

public TreeNode reLinkTree(TreeNode root) {
    if (root == null) {
        return null;
    }
    
    // 重新链接左子树
    TreeNode left = reLinkTree(root.left);
    
    // 重新链接右子树
    TreeNode right = reLinkTree(root.right);
    
    // 将左子树的最右节点与当前节点的右子节点连接
    if (left != null) {
        TreeNode temp = left;
        while (temp.right != null) {
            temp = temp.right;
        }
        temp.right = right;
    }
    
    // 将当前节点的右子节点指向左子节点
    root.right = left;
    
    // 清空左子节点
    root.left = null;
    
    return root;
}

TreeNode root = new TreeNode(1);
root.left = new TreeNode(2);
root.right = new TreeNode(3);
root.left.left = new TreeNode(4);
root.left.right = new TreeNode(5);

TreeNode newRoot = reLinkTree(root);