The Core Container consists of the Core, Beans, Context, and Expression Language modules whose detail is as follows:
- The Core module provides the fundamental parts of the framework, including the IoC and Dependency Injection features.
- The Bean module provides BeanFactory which is a sophisticated implementation of the factory pattern.
- The Context module builds on the solid base provided by the Core and Beans modules and it is a medium to access any objects defined and configured. The ApplicationContext interface is the focal point of the Context module.
- The SpEL module provides a powerful expression language for querying and manipulating an object graph at runtime.
The Data Access/Integration layer consists of the JDBC, ORM, OXM, JMS and Transaction modules whose detail is as follows:
- The JDBC module provides a JDBC-abstraction layer that removes the need to do tedious JDBC related coding.
- The ORM module provides integration layers for popular object-relational mapping APIs, including JPA, JDO, Hibernate, and iBatis.
- The OXM module provides an abstraction layer that supports Object/XML mapping implementations for JAXB, Castor, XMLBeans, JiBX and XStream.
- The Java Messaging Service JMS module contains features for producing and consuming messages.
- The Transaction module supports programmatic and declarative transaction management for classes that implement special interfaces and for all your POJOs.
The Web layer consists of the Web, Web-MVC, Web-Socket, and Web-Portlet modules whose detail is as follows:
- The Web module provides basic web-oriented integration features such as multipart file-upload functionality and the initialization of the IoC container using servlet listeners and a web-oriented application context.
- The Web-MVC module contains Spring’s model-view-controller (MVC) implementation for web applications.
- The Web-Socket module provides support for WebSocket-based, two-way communication between client and server in web applications.
- The Web-Portlet module provides the MVC implementation to be used in a portlet environment and mirrors the functionality of Web-Servlet module.
There are few other important modules like AOP, Aspects, Instrumentation, Web and Test modules whose detail is as follows:
- The AOP module provides aspect-oriented programming implementation allowing you to define method-interceptors and pointcuts to cleanly decouple code that implements functionality that should be separated.
- The Aspects module provides integration with AspectJ which is again a powerful and mature aspect oriented programming (AOP) framework.
- The Instrumentation module provides class instrumentation support and class loader implementations to be used in certain application servers.
- The Messaging module provides support for STOMP as the WebSocket sub-protocol to use in applications. It also supports an annotation programming model for routing and processing STOMP messages from WebSocket clients.
- The Test module supports the testing of Spring components with JUnit or TestNG frameworks.