No technology exists in a vacuum, and JPA is no different in this regard. Although the fat-client style of application demonstrated in the previous chapter is a viable use of JPA, the majority of enterprise Java applications are deployed to an application server, typically using Java EE web technologies, and possibly other technologies as well. Therefore it is essential to understand the components that make up a deployed application and the role of JPA in this environment.
We will begin with an overview of the major Java EE technologies relevant to persistence. As part of this overview, we will describe the ...