Introduction

Abstract

SummaryIn this chapter we presented an introduction to the Java Persistence API. We began with an overview of current standards for persistence, looking at JDBC, EJB, and JDO. In each case, we looked at the conditions forced on us by these frameworks and developed a view of what a better solution could be.In the Object-Relational Mapping section we introduced the primary problem facing developers trying to use object-oriented domain models in concert with a relational database: the impedance mismatch. To demonstrate the complexity bridging the gap, we presented three small object models and nine different ways to represent the same information.We concluded the chapter with a brief look at the Java Persistence API. We looked at the history of the specification and the vendors who came together to create it. We then looked at the role it plays in enterprise application development and introduced the feature set offered by the specification.In the next chapter we will get our feet wet with the Java Persistence API, taking a whirlwind tour of the API basics and building a simple application in the process.