Topics in This Chapter
Data Access Object
Web Service Broker
You want to encapsulate data access and manipulation in a separate layer.
Many real-world J2EE applications implement persistent objects as Business Object (374), which use POJOs or entity beans. An application with simpler requirements might forego using business objects and instead use Session Façades (341), Application Services (357), or other helper objects that directly access and manipulate data in the persistent storage. Such business objects and application components require access to business data in a persistent store.
Most enterprise applications typically use relational database management ...