I saw on net that books for OCMJEA 7 are available in market but looking at this forum and other ocmjea forums, i found that most of the people are still doing OCMJEA 5 or OCMJEA 6. Can somebody please suggest if i should prepare for OCMJEA 7. If yes, can somebody please tell the preferred books for OCMJEA 7.
That book hasn't been printed yet. (And I suspect they mean OCMJEA as even Oracle isn't talking about the OCMJEA 7 yet which means Apress can't have a topic outline yet.) This has happened before where Apress has had a book cover for an exam that never came to be or came to be later.
Study for OCMJEA 5 or 6. There is no OCMJEA 7 exam to take yet and won't be for a good while.