Dependency injection is a feature of the Spring Framework that allows objects to define their own dependencies, which the Spring container then injects into them. This allows developers to build modular programs with loosely linked components, which are perfect for microservices and distributed network applications.

Data binding, type conversion, validation, exception handling, resource and event management, internationalization, and other common tasks that an application must complete are all supported by Spring Framework. It works with RMI (Remote Method Invocation), AMQP (Advanced Message Queuing Protocol), Java Web Services, and other Java EE technologies. To summarize, Spring Framework gives developers all of the tools and capabilities they need to build loosely coupled, cross-platform Java EE applications that can run in any environment.

Spring Framework is capable and extensive, but configuring, setting up, and deploying Spring applications still takes effort and knowledge. With three key capabilities, Spring Boot reduces this work.

Autoconfiguration
Autoconfiguration refers to the fact that apps come with pre-configured dependencies that you don’t have to explicitly specify. Because Java Spring Boot has built-in autoconfiguration, it configures both the underlying Spring Framework and third-party packages based on your preferences (and based on best practices, which helps avoid errors). Despite the fact that you can alter these defaults once the startup is complete, Java Spring Boot’s autoconfiguration functionality allows you to quickly begin constructing Spring-based apps and eliminates the risk of human error.

Opinionated strategy
Spring Boot takes a hands-on approach to adding and customizing startup dependencies based on your project’s requirements. Spring Boot decides which packages to install and which default values to use based on its own judgment, rather than asking you to make all of those decisions and set up everything manually.

During the startup phase, you can define your project’s requirements by selecting from a list of starter dependencies (called Spring Starters) that address common use cases. You may use Spring Boot Initializr without coding by filling out a simple web form.

Standalone applications
Spring Boot enables programmers to construct apps that just run. By embedding a web server like as Tomcat or Netty within your program during the initialization phase, you may construct independent applications that function without the need for an external web server. As a result, you may use the Run command to launch your application on any platform. (If you don’t want to use an embedded Web server, you can disable this capability.)

In practice, though, utilizing Spring Booth is worth the tradeoff unless you need or want to design a particularly unique configuration. Spring Framework’s renowned annotation system, which lets you easily inject extra dependencies (not covered by Spring Starters) into your application, is still available. All Spring Framework features, such as easy event handling, validation, data binding, type conversion, and built-in security and testing capabilities, are still available. In the end, if even one Spring Starter covers your project’s scope, Spring Boot can dramatically speed up development.