What is the Spring Framework?

If you want to create Enterprise Java applications or Java Web applications, Spring Framework with Spring boot is a good option to look at. Today I'll explain to you what the Spring Framework is and how it helps you to create applications easily using Java with Spring Boot.

Watch the video below to find out what the Spring Framework is and how it will help you create web applications easily.

Transcript

Spring Framework is an open source framework that makes Java Enterprise development easier. A lot of the code and configurations that you would have needed to write in the past is now taken care of for you by Spring with the use of annotations.

It had its inception in 2003 as a response to the complexity of early J2EE specifications. It lived up to this in making enterprise development easier and is now the most popular application development framework for enterprise Java. It has evolved quite a lot since then and has a large and active community that gives feedback based on diverse real-world applications. This has enabled Spring to evolve over a long period of time.

Spring Framework is a lightweight and has a modular design. This means that you can include just the parts of it that you are going to use. You have the core of Spring at the centre of the framework which includes the configuration model and dependancy injection mechanism. Spring provides foundational support for different architectures, including Spring MVC for web, Spring JPA for persistence, Spring Mail for email and Spring Cloud for cloud-based architectures amongst others.

Spring allows developers to create enterprise level applications using POJOs (Plain Old Java Objects), instead of entity beans. The benefit of this is that you don’t need an application server to run your application, but you can deploy it on a lightweight, robust servlet container such as tomcat.

It also uses dependency-injection as an inversion of control method. This means that you can keep classes independent from each other so that they can be more reusable and easier to test too.

As from Spring 2.5 it became possible to configure dependancy injection using annotations. You can now use annotations on the component class itself to add beans and bean configuration into it.

Here are examples of some annotations:

• @Component - tells Spring that the class is a component and Spring will scan the class and add it to the ApplicationContext
• @Configuration - indicates that the class can be used by the Spring IoC (Inversion of Control) container as a source of bean definitions
• @Configuration - indicates that the class can be used by the Spring IoC (Inversion of Control) container as a source of bean definitions
• @Autowired - for dependency injection. It instantiates and autowires the attribute into your class.
• @Bean - a method level annotation that declares the adds the returned object of the method as a bean in the application context.

These are some of the annotations for Restful Webservices:

• @RestController - indicates that the data returned by each method will be written straight into the response body instead of rendering a template.

Spring Boot helps you to create stand-alone, production-grade Spring-based Applications that you can run. Most Spring Boot applications need very little Spring configuration. It is built on top of Spring Framework and it comes with many dependencies that can be plugged into the Spring application by using annotations or config files. It also offerers a built in web server like Tomcat or Jetty when needed.