Journey to the Spring World

Spring is an open source modular framework for the JVM platform. A framework is a collection of libraries whose primary goal is to address common software development problems. The framework should solve these problems in a generic form. 

Rod Johnson created the Spring Framework in 2002 together with his book publication, which was called Expert One-on-One J2EE Design and Development. The idea behind the creation of the framework was to tackle the complexities of Java Enterprise Edition.

At that time, this kind of solution-focused a lot on the details of the infrastructure, and a developer using the solution would spend a lot of time writing code to solve infrastructural problems. Since its creation, one of Rod Johnson's primary concerns has been to increase developer productivity.

The framework was first seen as a lightweight container for Java Runtime Environment, and it became popular in the community, especially because of the dependency injection feature. The framework made dependency injection incredibly easy. Developers hadn't seen such a feature before, and as a consequence, people the world over adopted the project. Year by year, its popularity within the software development world has been increasing.

In the earliest versions, the framework had to work with the XML file to configure the container. At the time, this was so much better than J2EE applications, where it was necessary to create many Ant files to create the boilerplate classes and interfaces.

The framework was always seen as an advanced technology for the Java platform, but in 2014, the Spring team launched the Spring Boot platform. This platform was incredibly successful in the Java Enterprise ecosystem, and it changed the way in which developers built Java Enterprise applications.

Today, Spring is the de facto framework for Java development, and companies around the world use it in their systems. The community is vibrant and contributes to development in different ways, such as opening issues, adding the code, and discussing the framework in the most important Java conferences around the world. Let's look at and play with the famous framework for Java developers.

We will cover the following topics in this chapter:

• Main modules of the Spring Framework
• Spring annotations for each module
• Setting up the development environment
• Docker and Docker commands