For a more thorough answer, see this web page
http://www.sun.com/training/certification/java/scjp.xml To quote the bit you need
"Sun Certified Java Programmer (SCJP) Overview
This foundation certification is for programmers interested in demonstrating proficiency in the fundamentals of the Java programming language.
To achieve this certification, candidates must successfully complete one exam. It is not necessary to be a Sun Certified Java Associate prior to taking this exam."
Hope this helps.