In principle, you could rename the classes on the class-file level after compilation, back to the original names. That wouldn’t violate the license.

Moreover, under the following definition in the license:

  `Modification' of a file
  means any procedure that produces a derivative file under any
  applicable law -- that is, a file containing the original file or
  a significant portion of it, either verbatim or with modifications
  and/or translated into another language.

…compilation would count as modification (“translated into another language”), and compilation also changes the file name (from .java to .class), so distributing the compilation output should be fine. Furthermore, any changes to the sources can be distributed as a diff patch, which also has a different file name.