Oracle's A-Team has developed a free JDeveloper extension called the "ADF Mobile Persistence Sample". This extension contains powerful design-time wizards and a comprehensive runtime library, allowing you to very quickly create a mobile application with data caching and data syncing capabilities. Check out this impressive video that shows the development process with this extension from start to finish.
More information can be found in two articles on the A-Team Chronicles website:
Oracle A-Team and Mobile Platform Product Management are currently investigating how the functionality of this extension can best be integrated in future releases of the product.