Java comes over with a framework that provides support for developing Java applications that we call Spring. It is a lightweight framework that supports different Java frameworks, such as hibernate, Struts and many more. Written by Rod Johnson it was licensed in 2003 under Apache 2.0.
It is an open-source java platform enabling POJO based programming model and extensions for building web applications. Spring comes with several layers that have modules with it which helps in framework support. Having spring helps developers to build an application with full speed concentrating focus over the functional and logical requirements of an application.
Spring provides various extension support with the help of which we can make our applications. Spring is modular in nature, being the quality as we can use the part we need for building any application rather than using the whole. It allows users to develop an application using POJO and one benefit of having POJO is that we can work with robust servlets containers rather than EJB containers.
Having Framework support makes the testing of code easier as all the environmental dependencies are handled over the framework. It has various modules that we can use based on the application requirement. It has a layered representation of the modules where we can easily pick up the modules be it core Container to Data Access, Web Services.
How Spring Works?
It comes with an IoC container that gets the information from the XML file and configures and assembles dependencies between the objects. Bean Factory and Application context are the two IoC container that does the required job.
Dependency Injection is used to loosely couple the code by removing the dependency of the program. We can use a Constructor or getter setter method to use the dependency Injection.
The Spring container gets the information about the objects with the help of XML files or the metadata files it has, it uses the POJO class and the application is executed with the final result ready to use.
Application of Spring Framework
Spring dues its lightweight and embedded functionalities are used for making complex java applications. We can definitely use spring over the model where we want our business logic to be separated with certain concerns such as logging, security, etc.
If we have lots of components over our application and we need to wind up them together spring can be a wise choice for developers. Even it comes out with lots of templates that are well-integrated and can be used for well functioning. example being the JDBC template used for connection with JDBC drivers. It supports transactions and we can also maintain the life cycle of an application with the help of spring.
As a programmer, someone having good knowledge over Java and object-oriented programming will found spring easy to learn and implement.
Dependency injection techniques and working with POJO classes will give us a better idea of how the spring framework is implemented and its usage over the application development.
For the reader, you should have good knowledge of object-oriented concepts, and how an object is made and handled over an application, further good coding knowledge is always an added advantage.