You could do SCDJWS without doing SCWCD and SCBCD but you need the have some knowlegde over servlets/jsp and
EJB because you can use them for making the webservice. So knowledge over them would be helpful. If you doesn't have knowledge over them then
you should learn this during the preparation of SCDJWS.
Remko (My website)
SCJP 1.5, SCWCD 1.4, SCDJWS 1.4, SCBCD 1.5, ITIL(Manager), Prince2(Practitioner), Reading/ gaining experience for SCEA,