Who Should Read This Book?

If you are a Java programmer who writes software that needs to store data beyond the duration of a single Java Virtual Machine (JVM) context, then you should read this book. We assume that you already know Java. But you don't need to have a lot of knowledge of databases, because JDO insulates you from needing to know much about them.

Many Java developers have been using Java Database Connectivity (JDBC) to store their data in a database. JDBC requires that you learn SQL. When you interact with a database via JDBC, you must view your information model from the perspective of the relational data model, which is very different from Java. Many developers never attain the advantages of object-oriented programming because they never define an object model for their persistent data. Most of the application software becomes very procedural-like code that manages data in the tables of the relational data model.

With JDO, Java becomes your data model and you only need to deal with instances of your classes when interacting with the database. Having just the single data model of Java as the basis of your data management simplifies your development task considerably.