Return stopover in Shanghai for a cruise to Japan

Please can you confirm we do not need to apply for a visa for entry to China before we leave UK and apply for this at the airport on arrival?
Our itinerary:
Arrive Shanghai airport, 2 night stay in hotel Shanghai;
Pick up cruise ship to Japan 7 days;
and return to Shanghai on the 9th day (15 hours) for flight back to UK.
Under the 240 hour policy, will we need to reapply for second visa free permit on reentry to China after the cruise…..or will one application suffice? Thanks.