What is Spring Boot

What is Spring Boot: Introduction to Spring Boot

Spring Boot is a light-weight Spring Framework that is used to develop the standalone and Spring-based applications. The Spring Boot project is built on the top of all the Spring Frameworks. It is developed by the Pivotal team. It takes most of the work out of configuring Spring-based applications. Spring Boot provides a faster way to set up, configure, and deploy basic and web-based applications.

The Spring Framework is useful for developing the Java enterprise applications with ease. It can be used with other frameworks as well such as Hibernate and Struts. It provides a production-ready applications. In Spring Boot we don’t need to create configurations because all the basic configurations are done by the Spring Boot. Spring Boot provides an embedded server in jar files.

Spring Projects Structure

All in all, Spring Boot is a project built on the top of the Spring framework.

Generally, it a Spring Module that provides Rapid Application Development to the Spring Framework. The Spring applications can be simply created and run with the help of Spring Boot because it needs minimal configuration.

We can say “Spring Boot is the combination of Spring Framework and Embedded Servers.”

The Spring Boot can be described as:

Spring Boot = Spring Framework + Embedded HTTP servers – XML Configurations
Spring Boot

Spring Boot does not require any XML configuration file (deployment descriptor). Comparatively, it uses convention over configuration. Thus, it reduces the effort of the developer.

The Spring Initializr or STS IDE can be used for creating a Spring Boot application. However, we can use other IDEs such as eclipse, Netbeans by configuring it.

Spring Boot Features

Some notable features of Spring Boot are as following:


Spring Boot provides autoconfiguration that helps for setting up your application on the relative environment.further, it hints what the developers provide.


The Spring Boot project is completely stand-alone which means you don’t need an additional web server or environment to deploy your application. You just have to run the project.


The Spring Boot project is opinionated which means the framework chooses the required things for itself.

Web Development

The web development module is one of the best modules of the spring framework. We can create the project contained an HTTP server with the help of embedded servers. Also, the spring boot starter web module is very useful for starting and running applications quickly.


The SpringApplication is a class which is used to bootstrap a Spring application. This application can be started from the main method. We can start our application by calling a run() method.

public static void main(String[] args){
SpringApplication.run(className.class, args);

Application Events and Listeners

The Spring Boot provides events which is used to handle a variety of tasks. it allows us to create factories files to add the listeners. It is referred to by using the ApplicationListener key.

Note: It is recommended to create factories file in META-INF folder like META-INF/spring.factories

Admin Support

The Spring Boot provides admin support which is used for managing and monitoring Spring Boot applications. Each application is treated as a client and registers to the admin server. It is enabled by using spring.application.admin.enabled property.

Externalized Configuration

The Spring Boot project can be externalized means we can work with the same application in different environments. The YAML file is used to externalize configuration.

Properties Files

The Spring Boot has a huge collection of Application Properties. It is used to set properties like: server-port = 8080 and other properties. It is useful for organizing the application properties.

YAML Support

It provides an easy way to specify the hierarchical configuration. The YAML file is a superset of JSON. The SpringApplication class automatically supports YAML. It is a powerful alternative to the properties.

Type-safe Configuration

It provides a strong type-safe configuration to control and validate the configuration of the application. The application configuration has always been a decisive task so it would be type-safe.


It uses a common logging for all internal logging. The logging dependencies are managed by default. There is no need to change the logging dependency if no required customization is needed.


Spring Boot applications are secure application as it is secure by default with basic authentication on all HTTP endpoints. A large set of endpoints are available for developing a secure Spring Boot application.

Advantage of Spring Boot

Following are some advantages of Spring Boot:

Easy to develop

The Spring Boot projects can be created easily with Java or Groovy.


Spring Boot provides many features such as auto-configuration, YAML support which saves time and increases productivity.

Reduces Line of Codes

It saves us from writing lots of unnecessary (boilerplate) codes, annotations and XML configurations.

Easy Integration

The Spring Boot project is very easy to integrate with the Spring ecosystem such as Spring JDBC, Spring ORM, Spring Data, Spring Security, and more.

Opinionated Default Configurations

It works on the Opinionated Defaults Configuration approach to reduce the effort of the developer.

Embedded Servers

It provides embedded HTTP servers for web applications such as Tomcat, Jetty, and more.

CLI (Command Line Interface)

It Supports CLI for developing and testing the Spring Boot applications from the command prompt.

Plugin Support

It provides support for various plugins for developing and testing the Spring Boot applications using different build tools such as Maven or Gradle. It also provides support for other plugins to work with embedded and in-memory databases.

Limitations of Spring Boot Framework

The Spring Boot has only one limitation that it is a bit complicated to convert a Spring Boot Project into other Spring Boot applications. On the other hand, we can easily convert all kinds of Spring-based projects into Spring Boot projects. It is easy to create a fresh Spring Boot project.

Goals of Spring Boot

The main goal of Spring Boot is to make the development and testing (Unit and Integration) easy and provide production-ready web applications. It provides a faster way as compared to other Spring frameworks.

Some main goals of using Spring Boot framework are as following:

  • Completely avoid the use of XML configurations.
  • To avoid the defining annotation configurations.
  • Freedom from writing plenty of import statements.
  • To Provide some quick-start options within no time.
  • To Provide an Opinionated approach for developing applications.

By using all of the above approaches, Spring Boot reduces the time, effort of a developer, and increases the productivity.

FAQs on Spring Boot

Following are some frequently asked question by the beginners:

Do I need to learn Spring before Learning Spring Boot?

The answer is no, you can learn Spring Boot without knowing Spring Framework. But, it is recommended and good to have some exposure to the Spring framework.

If we talk about the Spring Framework, it is more user friendly as compared to Spring Boot. So, if you start with Spring, you will better understand how things are going.

Is Spring Boot much popular?

The answer is Yes. Spring Boot is a very popular Java framework among developers.

Why is Spring Boot so popular?

The main reason behind the popularity of Spring Boot framework is that it makes use of Java one of the popular programming language among the developers in the world.

Excerpt from the above reason, several other reasons makes it very special and popular framework, such as:

  • simplicity
  • easy of development
  • Reduces the line of code
  • Provides Project ready applications
  • Can develop the major web applications.
  • Secure
  • Minimal configurations
  • Large community support

And many other features make it so popular.

What is NOT Spring Boot?

The Spring Boot framework is not meant for solving new problems. It is used to solve the same problems which Spring does

Why Spring Boot?

  • To provide the ease of development
  • To provide the ease of unit testing and integration testing
  • To reduce the development effort
  • To increase the production

How to start with Spring Boot?

Three approaches are provided by the Spring Team to start with Spring Boot:

  • Using Spring Boot CLI Tool
  • Using Spring STS IDE
  • Using Spring Initializr Website

In other Sections every approach and related aspects in detail with explained examples.

We can develop two types of application by using the Spring Boot:

  • Java-Based Applications
  • Groovy Applications

For Groovy we can follow the Spring Boot CLI, Spring STS IDE, or Spring Initializr Website approach for developing Spring Boot Java Applications.

For Java, we can use the Spring STS IDE or Spring Initializr Website approach for developing Spring Boot Java Applications.

However, the Groovy and Java can also be combined into one project. Because Groovy is also a JVM language almost similar to Java.

Groovy and Java