Introduction

Introduction to Spring Framework

Topics

• Spring History
• What is Spring
• Why Spring
• Spring architecture

Spring History

• Started 2002/2003 by Rod Johonson and Juergen Holler
• Started as a framework developed around Rod Johnson's book Expert One-on-One J2EE Design and Development
• Spring 1.0 Released March 2004
• …
• Spring 4.2.0 Released July 2015

What is Spring

• Spring Framework is an open source light-weight application framework that aims to make J2EE developement eaisier.
• Spring aims to help whole applications in a consistent and productive manner
• Used for building Java SE & Java EE applications

What is Spring - Key Features

• JavaBeans-based configuration management, applying Inversion-of-Control principles, specifically using the Dependency Injection technique.
• A core bean factory, which is usable globally
• Generic abstraction layer for database transaction management
• Built-in generic strategies for JTA and a single JDBC DataSource

What is Spring - Key Features

• Integration with persistence frameworks Hibernate, JDO and iBATIS
• MVC web application framework, built on core Spring functionality, supporting many technologies for generating views, including JSP, FreeMarker, Velocity, Tiles, iText, and POI
• Extensive aspect-oriented programming(AOP)

Why Spring

• Problems with Traditional Approach to J2EE …
  • The EJB component model is complex
  • EJB is designed for distributed, transactional applications. While all non-trivial applications are transactional, distribution should not be built into basic component model
  • J2EE applications are hard to unit test

Why Spring

• Responses to problems was tool support to catch up with J2EE specifications, e.g code generations tools
• Spring aims to take away problems, by simplifying the programming model, rather than concealing complexity behind the complex layer of the tools
• The essence of the Spring is in providing eneterpise sevices to Plain Old Java Object(POJOs). This is valuable in a J2EE enviroment, but application code delivered as POJOs is naturally resuable in variety or runtime enviroments

Why Spring

• Wiring of components through Dependency Injection
• Design to interfaces
• Test-Driven Development (TDD)
• POJO classes can be tested without being tied up with the framework

+++

• Declarative programming through AOP
  • Integration with other technologies
  • EJB for J2EE
  • Hibernate, iBatis, JDBC (for data access)
  • Velocity (for presentation)
  • Struts and WebWork (For web)

Overview of the Spring Framework

• Inversion of Control container
  • Dependecy Injection
• Aspect-Oriented Programming(AOP) framework
• Data Access abstracion
• JDBC simplification

+++

• Transation Management
• MVC web framework
• Simplification for working with JNDI, JTA
• Lightweight remoting
• JMS support
• Support for testing

Overview of the Spring Framework

Overview of the Spring Framework - Core Package

• Core package is the most fundamental part of the framework and provides the IoC and Dependency Injection features
• The basic concept here is the BeanFactory, which provides a sophisticated implementation of the factory pattern which removes the need for programmatic singletons and allows you to decouple the configuration and specification of dependencies from your actual program logic

Overview of the Spring Framework - DAO Package

• The DAO package provides a JDBC-abstraction layer that removes the need to do tedious JDBC coding and parsing of database-vendor specific error codes
• The JDBC package provides a way to do programmatic as well as declarative transaction management, not only for classes implementing special interfaces, but for all your POJOs (plain old Java objects)

Overview of the Spring Framework - ORM Package

• The ORM package provides integration layers for popular object-relational mapping APIs, including JPA, JDO, Hibernate, and iBatis.
• Using the ORM package you can use all those O/R-mappers in combination with all the other features Spring offers, such as the simple declarative transaction management feature mentioned previously

Overview of the Spring Framework - AOP Package

• Spring's AOP package provides an AOP Alliance-compliant aspect-oriented programming implementation allowing you to define, for example, method-interceptors and pointcuts to cleanly decouple code implementing functionality that should logically speaking be separated
• Using source-level metadata functionality you can also incorporate all kinds of behavioral information into your code

Overview of the Spring Framework - MVC Package

• Spring's MVC package provides a Model-View-Controller (MVC) implementation for web applications
• Spring's MVC framework is not just any old implementation; it provides a clean separation between domain model code and web forms, and allows you to use all the other features of the Spring Framework