check out the Sun recertification policy:
What was Sun's original Recertification Policy?
On September 1, 2002 Sun instituted an expiration policy for all of its certification exams taken after that date. The policy indicated that your certification was valid for a period of two (2) years from the date of certification. Recertification was required to maintain one's status as a certified Sun professional after two years.
The certification date appeared on both the certificate and the identification card with the applicable certification title that were provided to successful candidates. The identification card also included the expiration date, which identifies when an IT professional's Sun certification status expires.
What is Sun's new Certification Policy?
Beginning with all Sun certification exams taken on or after August 1, 2003, certification offerings from Sun no longer have an expiration date. Rather, certification offerings are based on a version of technology. The certification date and exam version will appear on both a certificate and an identification card with the applicable certification title.
Recertification is no longer required to maintain one's status as a certified professional. Sun certification is now directly associated with a version of technology. Nevertheless, Sun highly recommends that you remain certified at the most current technology version.
When will the Certification Policy take effect?
The new Certification Policy will take effect on August 1, 2003.
If a Sun certified professional has already received a certificate and ID card with the printed expiration date, can that professional request another certificate and ID card without an expiration date?
Yes. The certified professional will need to send an email to the who2contact@sun.com alias to request a new certificate and ID card. Include your name and Prometric Candidate ID number.
How long is my Sun certification title now valid?
As of August 1, 2003, all Sun certifications are now based on versions. There is no expiration date to your certification title. You may, however, be certified on a technology that is outdated if Sun releases a new exam associated with a new technology version. Keeping your certification current is highly recommended.
so in a nutshell -- if you took the exam after Aug. 2003 your cert will never really expire. The technology will just become out of date and thus less valued by the industry. Currently the
SCJP upgrade exam and the
SCJD exam just says you have to have a previous SCJP certification (any edition). But of course
you should check with Sun when you're ready to take a new exam to make sure you qualify for it.