Judge two trees as isomorphic java

boolean isSame(TreeNode root1,TreeNode root2){
    
    
  if(root1 == null && root2 == null){
    
    
    return true;
  }
  if((root1 == null && root2 != null) &&
      root1 != null && root2 == null)){
    
    
    return false;
  }
  return isSame(roo1.getRight(),root2.getRight()) && isSame(root1.getLeft(),root2.getLeft());
}