Spring Framework

Framework:-

• Frameworks are the ultimate time-savers for anyone looking to perform tasks efficiently. By utilizing pre-built software solutions, frameworks eliminate the need for tedious coding and enable you to focus on business logic more.
• With the help of a framework developing becomes easy. e.g. Spring, Hibernate, etc.
• It reduces the complexity of an object.

Spring Framework:-

• Spring is a Java-based application that is used to develop enterprise(e-commerce) applications. e.g. Amazon, Flipkart, Naptol, etc.
• Spring is also a dependency injection framework.
• Spring is a helpful tool for developing loosely coupled applications. With Spring, you can easily build applications that are not tightly bound.

Important Definitions in Spring Framework

Inversion of control (IOC):-

• It is the process of transferring control of an object to the spring framework is called inversion of control.
• In other words, IOC is a process wherein the control of an object (creating and injecting the object) is transferred to the spring framework.
• IOC is achieved with the help of dependency injection.

Dependency Injection:-

• Dependency Injection is a design pattern that is used to achieve inversion of control(IOC).
• It is used to inject or insert one object into another object.
• There are two types of dependency injection.

1. Property Injection.
2. Constructor Injection. 

Design pattern:-

• A design pattern is a solution to a problem that occurs repeatedly in a project.
• A design pattern is a typical solution or general solution to all the commonly occurring problems.
• Example:- Singleton Design pattern and Dependency Injection.

Spring Container or Spring IOC Container:-

• A spring container is a component that is responsible for creating an object, storing an object in the memory and injecting the object whenever it is necessary.
• In simple words, Spring Container is responsible for the lifecycle of an object.
• <<ApplicationContext>> is a predefined interface that manages the lifecycle of an object.

Note:-

• We consider Application Context as our Spring Container.

Implementation classes of ApplicationContext:-

1. ClassPathApplicationContext
2. FileSystemXmlApplicationContext
3. WebXmlApplicationContext
4. AnnotationConfigApplicationContext

Note:-

• For the Spring Container, we need to provide the information regarding bean class and configuration.

Mandatory rules for creating Java Bean class:-

• public non-abstract class
• private data members
• public getter and setter method.

Steps to achieve dependency injection (setter or property injection):-

• Create a Java project with the respective package.
• Download the Spring Jar files and add them to the build path.
• Create a Bean Class with respect to the getter and setter method.
• Create a configuration file (XML file).
• Search for the configuration file get the bean and utilize the bean.