Nothing like a framework to ease your burden.  Check it out, more than 50 java development frameworks are described and linked.  Of course the usual suspects are here: Cocoon, Struts, and Java Server Faces.  But also includes Tapestry, RSF, ZK and JAT.  Wow, glad we are finally moving into this space...

The OAICat Open Source Software (OSS) project is a Java Servlet web application providing a repository framework that conforms to the Open Archives Initiative Protocol for Metadata Harvesting (OAI-PMH) v2.0. This framework can be customized to work with arbitrary data repositories by implementing some Java interfaces. Demonstration implementations of these interfaces are included in the webapp distribution.