It depends on how much you need to learn and how high you want to score. I would suggest:
- try one of the mock exams to see how much you need to learn/refresh
- refresh your java knowledge using the K & B book. You can finsih it in about 10 days if you can read one chapter a day.
- try as many mock exams as you can to get close to your score/goal.
If you just want to pass the
test, I think you can do it in 4 weeks.