POJO - Plain Old Java Object

[kuldeeprsks]

A POJO is a Java object that doesn't implement any special interfaces such as those defined by the EJB 2 framework.

POJOs also accelerate development. You can test your business logic outside of the application server and without a database. You don't have to package your code and deploy it in the application server. You also don't have to keep the database schema constantly in sync with the object model or spend time waiting for slow-running database tests to finish. Tests run in a few seconds and development can happen at the speed of thought - or at least as fast as you can type!

POJOs often have to be persisted in a relational database. For example, the Money Transfer application must store Account objects in the ACCOUNT table. It could, of course, access the database using JDBC or iBATIS. Sometimes this is the right approach. But unless you have a really simple object model, it can be a lot of work to develop and maintain the Data Access Objects (DAOs) and the SQL needed to transfer objects to and from the database. It's usually a lot easier to use an ORM framework.