Thanks to coderanch and enthuware.
Preparation tips:
Pro JPA2 is my primary study material, and also read
JPA 2.0 Spec.
Make good use of
Enthuware's JPAD 6.
Make sure you read all explanation from each question, it's your key to success.
OCAJ, SCJP, SCWCD, SCBCD, OCEJPA, OCUP Fundamental, OCA, BEA 8.1 Certified Administrator, IBM Certified SOA Solution Designer