Agenda Overview:• What is Spring ?• History of Spring• Features of Spring• Why Spring ?• What does Spring offer?• Goal of Spring• Modules of Spring• Types of layers• Application Layering• Where to use Spring ?• Conclusion
What is Spring:What is Spring:• Spring is an open source framework created to address the complexity of enterprise application development• One of the chief advantages of the Spring framework is its layered architecture, which allows you to be selective about which of its components you use while also providing a cohesive framework for J2EE application development.• It makes the application easy to configure and reduces the need for many J2EE design patterns. Spring can be used to configure declarative transaction management
History of Spring :• The first version of Spring Framework was developed by Rod Johnson. Its first version was released with the publication of the book Expert One-on-One J2EE Design and Development in the October 2002.• Year 2002, Rod Johnson release its first version• March 2004, first version release under Apache 2.0 license• In Year 2004 and 2005 further milestone release was make available to the developers• Year 2006 Spring 1.2.6 released• In December 2009, version 3.0 GA was released• June 15, 2010, Spring 3.0.3 released• Dec 12th,2011, Spring 3.1.0 GA was released• Sep 10th,2012, Spring 3.2 M2 released
Features of Spring :• Spring is Lightweight container• No App Server Dependent – like EJB JNDI Calls• Objects are created Lazily , Singleton - configuration• Components can added Declaratively• Initialization of properties is easy – no need to read from properties file• Declarative transaction, security and logging service – AOP• application code is much easier to unit test• With a Dependency Injection approach, dependencies are explicit, and evident in constructor or JavaBeans properties• Springs configuration management services can be used in any architectural layer, in whatever runtime environment.• Spring can effectively organize your middle tier objects• Not required special deployment steps
Why Spring :• The Spring Framework was developed to ease the development of Enterprise Java applications• Reducing the writing code while development application.• Easy to integrate with any existing framework• Needed a solution to loosely couple business logic in a POJO fashion.• Wanted to build portable applications that provided clearer separation of presentation, business, and persistence logic.• Simplify use of popular technologies handle common error conditions• Well designed ▫ Easy to extend ▫ Many reusable classes
Simplify your code with Spring :• Enables you to stop polluting code• No more custom singleton objects ▫ Beans are defined in a centralized configuration file• No more custom factory object to build and/or locate other objects• DAO simplification ▫ Consistent CRUD ▫ Data access templates ▫ No more copy-paste try/catch/finally blocks ▫ No more passing Connection objects between methods ▫ No more leaked connections• POJO Based• Refactoring experience with Spring• Caution Spring is addictive!
What does Spring offer?• Dependency Injection ▫ Also known as IoC (Inversion of Control)• Aspect Oriented Programming ▫ Runtime injection-based• Portable Service Abstractions ▫ The rest of spring ORM, DAO, Web MVC, Web, etc. Allows access to these without knowing how they actually work• Spring Security
Spring is Non-Invasive :• What does that mean ? You are not forced to import or extend any spring APIsAnti-Patterns• EJB force you to use JNDI• Struts force you to extend Action, ActionSupport• Invasive frameworks are inheritently difficult to test(especially unit test)• You to stub the runtime that is supplied by the application server.
Layer’s are 4 types:1.Presentation or UI (User Interface) Layer (Struts/Jsps/JSF/Velocity etc.)2.Bussiness or Service Layer (Servlets/EJB/Spring)3. Data Access Layer or Persistence layer (ORM’s or JDBC) (Hibernate/JPA/Ibaties/Toplink etc.)4. Data Layer (Database) (MySql/Oracle/IBM DB2/Postgress/Ingress/ SQL Server etc.)
Application Layering :• A clear separation of application component responsibility. ▫ Presentation layer Concentrates on request/response actions Handles UI rendering from a model. Contains formatting logic and non-business related validation logic. Handles exceptions thrown from other layers ▫ Persistence layer Used to communicate with a persistence store such as a relational database. Provides a query language Possible O/R mapping capabilities JDBC, Hibernate, iBATIS, JDO, Entity Beans, etc. ▫ Domain layer Contains business objects that are used across above layers. Contain complex relationships between other domain objects May be rich in business logic May have ORM mappings Domain objects should only have dependencies on other domain objects
What about a Service Layer?•Where do we position loosely-coupled business logic?• What is service logic?• How should container level services be implemented?• How do we support transactions in a POJO based application?• How do we communicate from our presentation layer to our persistence layer?• How do we get to services that contain business logic?• How should our business objects communicate with our persistence layer?• How do we get objects retrieved from our persistence layer to our UI layer?
Application Layering (cont):▫ Service layer Gateway to expose business logic to the outside world Manages ‘container level services’ such as transactions, security, data access logic, and manipulates domain objects Not well defined in many applications today or tightly coupled in an inappropriate layer.
Such a combination allows the development of you web applicationswith maximal of flexibility and minimal effort
More Application Layering Combinations :Presentation/Business/Persistence• Struts+Spring+Hibernate• Struts +Spring + EJB• JSF+ Spring + JPA/ iBATIS• Spring + Spring + JDO• Flex + Spring + Hibernate• Struts + Spring + JDBC• You decide…
Conclusion :• Layered architecture application development is Long life with strong flexibility.• Migrating from an any framework is very easy in future.• Technology independent application development is providing loose coupling and portability, that supports spring.
Spring Books :• Spring in Action –by Craig walls and Ryan Bredenbach• Pro Spring-by Rob Harrop and Jan Machacek• J2EE Without EJB-by Rod Johnson and Juergen Holler• Expert One-on-One J2EE Design and Development- by Rod Johnson• Spring Developers Notebook- by Bruce tate and justin Gehtland• Spring Live- by matt Raible• Professional Java development With the Spring Framework –Rod & others