I need to get a value of ListenableFutureCallback from the delete function of asyncresttemplate

Question

I have a problem getting an object from ListenableFutureCallback when I use delete function of AsyncRestTemplate. This is my source code:

    ListenableFutureCallback<Object> callbackDelete = new ListenableFutureCallback<Object>() {
                @Override
                public void onFailure(Throwable ex) {
                    logger.error("Error processing the delete request: " + ex.getMessage());
                }

                @Override
                public void onSuccess(Object result) {
                    System.out.println("Async Delete Success : " + result.toString() );
                    logger.debug("The request has been processed successfully");

                }
            };


    ListenableFuture<?> response = asyncRestTemplate.delete(DELETE_URL + "/" + id);
    response.addCallback(callbackDelete);

When I execute result.toString(), result is always null.

Thanks