At long last, the JDeveloper IDE acknowledges Folders as a construct that the developer needs control over. Until now, folders were visible in JDeveloper because they existed on the file system. They could not be manipulated from within the IDE. Now, in the 12.1.3 release, they can be created, from the New Gallery:
Assigned a name and a location (parent folder):
and presto:
Through refactor, folders can be renamed:
and moved to another location: