Spring Introduction

                                                     Spring Framework

                       

                       

Q. What is a spring application?

A. Any enterprise Java application developed by using spring is know as spring application.

Q. What is not spring?

A. -> Spring is not a programming language unlike Java.

   -> Spring is not a technology unlike JDBC, Servlet, JSP and EJB.

   -> Spring is not a specification from SUN Microsystem.

   -> Spring is neither J2SE nor J2EE.

Q. What is Spring Framework?

A. Spring is a light weight, open source Java application framework.

-> Spring is a software product(jar) to be installed into a computer system in order to develop spring application.

-> Spring is considered as framework of framework because spring can be used in all the layer.

History of spring framework:

Q. How is Spring light weight?

A. Spring is light weight in terms of :

-> Processing Overhead.

-> container size.

-> Testability.

-> POJO programming model.

Q. Where is Spring used?

A. Spring is used in to implement all the layer of Java enterprise application.

Q. What is Spring Bean.

A. A spring container managed Java class is nothing but a spring Bean.

Q. What are the elements of a spring application?

A. 1. Controllers.

   2. Business components.

   3. Data Access Objects.

  

Q. What is the architecture of a Spring application.

A. 

In the above architecture flow works as below.

            1. Dispatcher Servlet which is a built-in Servlet provided by spring framework acting as from controller, receives the client request, capture the user input and

      perform the validation on the user input.

   2. Dispatcher Servlet invoking the sub controller methods for the remaining use case specific flow control sake.

   3. Sub controller bean invoking the business method of Service bean (business component).

   4. Business component for enterprise data invoking the DAO method of DAO bean.

   5. DAO method performing CRUD operation with database.

   6. DAO bean which is the dependency for service bean returning the CRUD operation result to its dependent.

   7. Business component which is a dependency of sub controller returning the result of data processing to its dependent(controller bean).

   8. Controller bean returning view mapping information to front controller =.

   9. Front controller switching the control to appropriate view.

   10. View component producing the response page for the client.

Q. Explain about spring architecture.

A. Spring framework is divided into the following major modules that forms the spring architecture:

 -> IOC module.

 -> AOP module.

 -> JDBC & DAo module.

 -> ORM module.

 -> JEE module.

 -> Web MVC module.