Why Solrj Default Format is XML Rather than Javabin?

[Furkan KAMACI]

Hi;

When I index documents via Solrj it sends documents as XML. Solr processes
it with XMLLoader. Then sends response as javabin format.

Why Solrj client does not send data as javabin format as default?

PS: I use Solr 4.5.1

Thanks;
Furlan KAMACI