Spring Overview

Overview

Spring addressed inconveniences encountered when using EJB as the primary framework.
Code introduced in Rod Johnson’s 2002 book, “Expert One-on-One J2EE Design and Development,” became the foundation of Spring.
Developers who read the book felt the code was too valuable to remain only in a book and developed it into a framework with Rod Johnson’s permission.
The Spring Framework was first released under the Apache 2.0 License in June 2003.
Version 1.0 was released in March 2004, and version 3.1 was released in December 2011.

Although it is commonly called Spring, the precise name is Spring Framework.

It is an open source application framework for the Java platform.
It is a lightweight, open source application framework that makes Java enterprise development easier.
It creates and assembles dependent objects for Java development.
It connects Java SE objects, or POJOs, without making them dependent on Java EE.

A lightweight container that directly manages Java objects
- It manages object life cycles, including creation and destruction, and provides required objects.
A POJO (Plain Old Java Object) framework
- https://en.wikipedia.org/wiki/Plain_old_Java_object
- It makes it easy to support existing libraries.
Supports IoC (Inversion of Control)
- The framework, rather than the user, owns control and invokes user code when needed.
Supports DI (Dependency Injection)
- The framework connects layers or services that depend on each other.
Supports AOP (Aspect-Oriented Programming)
- Common features used across modules, such as transactions, logging, and security, can be separated and managed independently.
Supports various persistence-related services
- It provides interfaces for integrating mature database libraries such as iBatis and Hibernate.
Highly extensible
- Existing libraries can often be used with Spring by wrapping them with a simple integration layer. Many libraries already support Spring, and Spring-specific integrations can be separated easily.

Spring Core
- Provides the IoC, or DI, foundation of the Spring Framework and controls bean classes through BeanFactory.
Spring Context
- Builds on Spring Core with additional features for easier development, including adapters for JNDI and EJB.
Spring DAO
- Supports easier and more consistent JDBC-based DAO development with less code.
Spring ORM
- Supports integration with object-relational mapping frameworks such as Hibernate, iBatis, and JDO.
Spring AOP
- Provides Aspect-Oriented Programming support based on the AOP Alliance.
Spring Web
- Supports web application development features such as WebApplicationContext and multipart requests, and integrates with frameworks such as Struts and WebWork.
Spring Web MVC
- Provides an independent Model-View-Controller implementation for the web UI layer. It can replace functionality previously handled by Struts and WebWork and provides APIs for UI technologies such as Velocity, Excel, and PDF.