Applications with a Web-based presentation layer can use JDO in at least two different ways:
Integration of JDO with an EJB service-oriented architecture and Data Transfer (Value) objects was discussed in depth in an earlier chapter. Such an approach could use a Web UI without JDO access from the presentation layer.
In another architecture, the JDO API could be used directly in the Servlet layer, including JSP pages as views. This approach is discussed briefly here.
The second architecture is straightforward: The business logic is in plain old Java objects (POJO) co-located to the presentation tier. The business logic and the presentation layer (Servlets and JSP) can use the JDO API directly.
In a Model-View-Controller (MVC) ...