My personal opinion is that learning C++ before java is not necessary.

A good textbook of java is all you require.

Since you are already familiar with Javascript, you can directly jump in to java.

Regards,
Paramesh.

"Don't walk behind me; I may not lead.
 Don't walk in front of me; I may not follow.
 Just walk beside me and be my friend."

Personally, I started with Java. That helped me IMMENSELY because in my current position it allowed me to move backwards and learn C++ with ease and move forwards and learn C# with ease (forward and backwards are my personal opinions on the complexity of the languages - backwards being more complex).