Ten Technologies Every Java Developer Should Know

1. At least one MVC Framework like JSF, Struts, or Spring MVC
2. Hibernate or JPA
3. Dependency Injection (as demonstrated in Spring or Java EE through @Resource)
4. SOAP based Web Services (JAX-WS)
5. Some build tool (Ant, Maven, etc.)
6. JUnit (or other Unit Testing framework)
7. Version control
8. JSTL
9. Application server/container configuration management and application deployment (whether it is WebSphere, Tomcat, JBoss, etc. you need to know where your application runs and how to improve its execution).
10. AJAX

Source: http://www.intertech.com