You can use anything based on
Java EE technology -
JSP,
Servlet, EJB,
JSF, Java Web Services (JAXB, JAXR, JAX-WS, JAX-RS, etc), JMS, RMI, JNDI, JavaMail,
Struts, Spring, Spring Web MVC, Spring AOP, Acegi Security, JAAS,
Tomcat,
JBoss, GlassFish, ... (you can fill anything you want).
SCJA 1.0, SCJP 1.4, SCWCD 1.4, SCBCD 1.3, SCJP 5.0, SCEA 5, SCBCD 5; OCUP - Fundamental, Intermediate and Advanced; IBM Certified Solution Designer - OOAD, vUML 2; SpringSource Certified Spring Professional