Question

I’m starting to program in Java (with the Spring Framework) and finding myself confused about the difference between DAOs and Spring’s Beans. Do they serve to the same purpose?

Answer 1

DAO == Data Access Object. It’s one way to write a persistence layer.

Spring can manage DAO beans and lots of other kinds, like message-driven beans, services, web controllers, and anything else you can encapsulate into a bean.

Spring has three parts:

1. Inversion of Control (IOC). Think of Spring as a big factory for creating and managing beans.
2. Aspect-oriented programming (AOP). This is how Spring manages cross cutting concerns like logging, transactions, proxying, remoting, and other activities that otherwise would be littered throughout your application.
3. Framework code, like the persistence templates for JDBC, Hibernate, TopLink, etc.; remoting; web MVC; etc. They write better code than we do – you get to just use it.