Spring Module

The Spring framework is made up of seven well-defined modules (figure 1.1).The core container
Spring’s core container provides the fundamental functionality of the Spring framework. In this module you’ll find Spring’s BeanFactory, the heart of any Spring-based application. A BeanFactory is an implementation of the factory pattern that applies IoC to separate your application’s configuration and dependency specifications from the actual application code.
Application context module
The core module’s BeanFactory makes Spring a container, but the context module is what makes it a framework. (The Spring context is a configuration file that provides context information to the Spring framework). This module extends the concept of Bean-Factory, adding support for internationalization (I18N) messages, application life cycle events, and validation.
In addition, this module supplies many enterprise services such as e-mail, JNDI access, EJB integration, remoting, and scheduling. Also included is support for integration with templating frameworks such as Velocity and FreeMarker.
Spring’s AOP module
Spring provides rich support for aspect-oriented programming in its AOP module. This module serves as the basis for developing your own aspects for your Spring-enabled application.
JDBC abstraction and the DAO module
Working with JDBC often results in a lot of boilerplate code that gets a connection, creates a statement, processes a result set, and then closes the connection.
Object/relational mapping integration module
For those who prefer using an object/relational mapping (ORM) tool over straight JDBC, Spring provides the ORM module. Spring doesn’t attempt to implement its own ORM solution, but does provide hooks into several popular ORM frameworks, including Hibernate, JDO, and iBATIS SQL Maps.
Spring’s web module
The web context module builds on the application context module, providing a context that is appropriate for web-based applications.
The Spring MVC framework
Spring comes with a full-featured Model/View/Controller (MVC) framework for building web applications. Although Spring can easily be integrated with other MVC frameworks, such as Struts, Spring’s MVC framework uses IoC to provide for a clean separation of controller logic from business objects.