Do I need to pick up luggage and go through immigration and customs transiting through XMN on CA 978

I am flying CA 978 from CGK to PEK. I understand the flight stops at XMN for 1 hour, and becomes a domestic flight thereafter to PEK. Do I need to clear immigration at XMN, and do I need to retrieve and recheck in my luggage at XMN? What is the procedure for such transit passengers?

Thanks.