Spring is the most popular application framework for Java Development Created in 2003. The Spring community is super active and vibrant, that's why a lot of companies love it.

Common Links:

• Official Website
• Spring Initializr

Spring aims to make Java Development lightweight by minimizing boilerplate code, promote loose coupling (independent java classes) with dependency injection, and encourage Java POJOs (Plain-Old-Java-Objects), as opposed to the Enterprise Java Beans (EJB) of the J2EE (1999).

• Core Container Layer - manage creation and availability of Beans (A serializable object with private properties and a constructor with no arguments, according to the JavaBean standard created in 1996),

• Infrastructure Layer - create services with Aspect Oriented Programming (AOP), where you can add functionalities (e.g. Logging, Security, transactions) declaratively. Monitor App with JMX (Java Management Extension)

• Data Access Layer - communicate with database with Spring JDBC helper classes, ORM (for integration with Hibernate), JMS (Java Message Service), and add transaction support

• Web Layer - home of Spring MVC where you can build web apps with Spring Core, Spring Controllers, Spring View. It also contains modules to interface with other popular web technologies like JavaServer Faces (2001) or Struts (2000)

• Test Layer - support test-driven-development(TDD) where you can use mock objects (simulations) to mock out servlets in a controlled testing environment, JNDI access, and creation integration tests

Spring projects are additional modules built-on top of the Spring Framework, some common ones are Spring Cloud, Spring Data, Spring Security, Spring Web Services, etc. It is like various libraries developers created.

Spring is Modular by Design

1. Maven
2. Spring Boot 3