Is it necessary for me to be certified as a Java Programmer and Developer before taking up the Java Architect exam?

No. There are no prerequisites for Sun Certified Enterprise Architect (SCEA). Where as to earn Sun Certified Java Developer (SCJD), one must be a Sun Certified Java Programmer (SCJP).

SCEA is a three-part exam, and clearing of each part will make the candidate eligible for next level.

For more information see http://suned.sun.com/USA/certification/archdetails.html