From the last couple of months, I have been helping a few developers to prepare for Java 8 associate certification with exam code 1Z0-808, also known as OCAJP 8. From my experience, both for preparing for Sun certification and helping other developers to get Java certified, I can say that two keys to be successful in Oracle Java SE certification are choosing an excellent study guide/course and buying one or two top quality mock exam simulators. When I say success, it doesn't mean just passing the exam but scoring above 90% because passing score 65% is not very difficult to achieve and anybody can pass OCAJP 8 by just a couple of month of practice but to score 90% and above is not that easy, you need to prepare and prepare hard.