Chapter 5. Mapping Data

Now that we’re in a position to work with Hibernate, it’s worth pausing to reflect on the big picture, lest we remain lost in the reeds of installation and configuration. Object-oriented languages such as Java provide a powerful and convenient abstraction for working with information at runtime in the form of objects that instantiate classes. These objects can link up with each other in myriad ways and can embody rules and behavior as well as the raw data they represent. But when the program ends, all the objects swiftly and silently vanish away.

For information we need to keep around between runs or share between different programs and systems, relational databases have proven hard to beat. They’re scalable, reliable, efficient, and extremely flexible. So what we need is a means of taking information from a SQL database and turning it into Java objects, and vice versa.