•  Spring is a powerful open source, application framework created to reduce the complexity of enterprise application development.
•  It is light-weighted and loosely coupled.
•  It has layered architecture, which allows you to select the components to use, while also providing a cohesive framework for J2EE application development.

A Spring application, generally consists of following components:

• Interface: It defines the functions.
• Bean class: It contains properties, its setter and getter methods, functions etc.
• Spring Aspect Oriented Programming (AOP): Provides the functionality of cross-cutting concerns.
• Bean Configuration File: Contains the information of classes and how to configure them.
• User program: It uses the function.

In Dependency Injection, you do not have to create your objects but have to describe how they should be created. You don’t connect your components and services together in the code directly, but describe which services are needed by which components in the configuration file. The IoC container will wire them up together.

•  BeanFactory: BeanFactory is like a factory class that contains a collection of beans. It instantiates the bean whenever asked for by clients.
•  ApplicationContext: The ApplicationContext interface is built on top of the BeanFactory interface. It provides some extra functionality on top BeanFactory.

1.  Test
2. Spring Core Container
3.  AOP, Aspects and Instrumentation
4.  Data Access/Integration
5.  Web

•  JdbcTemplate
•  SimpleJdbcTemplate
• NamedParameterJdbcTemplate
• SimpleJdbcInsert
• SimpleJdbcCall

Controllers provide access to the application behavior. These behaviors are generally defined through a service interface. Controllers interpret the user input and transform it into a model which is represented to the user by the view. In Spring, controller is implemented in a very abstract way. It also enables you to create a wide variety of controllers.

An object which is created after applying advice to a target object is known as a Proxy. In case of client objects the target object and the proxy object are the same

It is an alternative container configuration to the previously mentioned XML. This type of configuration is mainly focused on the bytecode metadata.

Bean wiring or wiring is the process of combining beans with the Spring container. It is essential to tell the container what beans are required and how it should use dependency injection to wire or tie them together.