Experience is recommended but not required for the exam. Take a few mock exams to see what level you're at now, and then you'll know how much more preparation you'll need.
If you already have better core java grip...and you just want to pass...it's not essential to prepare...just practice 10 to 20 mock exams..that's it.. But you mind to secure more socre...you need atleast 2 to 3 months hard preparation...
Any way all the best...
My first bit of advice is that if you are going to be a mime, you shouldn't talk. Even the tiny ad is nodding:
a bit of art, as a gift, that will fit in a stocking