如何从App Engine cron作业访问私有Fusion Table？

I have created several private tables in Fusion Table. These tables should be accessed and modified regularly by a cron job from my App Engine java web app. Could you please point me to example code or give me some guidance? And to be clear - I do not want users of my web app to gain access to the private tables, just the cron job should have access.I have created several private tables in Fusion