Spring Boot Initializer

SpringApplication:

The SpringApplication class provides a convenient way to bootstrap a Spring application that will be started from a main() method. In many situations you can just delegate to the static

SpringApplication.run method:

• SpringApplication is one of the Spring Boot API classes.
• SpringApplication class is used to bootstrap a Spring application that will be started from a main() method

package com.programingsoeasy;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

@SpringBootApplication
public class MySpringBootAppApplication {

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

MySpringBootAppApplication class is annotated with @SpringBootApplication annotation.

@SpringBootApplication does the following things:

• Because of @Configuration annotation, It scans for @Bean methods to create beans.
• Because of @ComponentScan annotation, It does component scanning (Components means Beans annotated with @Component,@Service,@Repository,@Controller etc).
• Because of @EnableAutoConfiguration annotation, It triggers Spring Boot Auto-Configuration.

When we run MySpringBootAppApplication class main() method, it make a calls to “SpringApplication.run()” method. Then this call done following things

• This call is used to create “AnnotationConfigEmbeddedWebApplicationContext”.
• This “AnnotationConfigEmbeddedWebApplicationContext” instance is used to create an instance of “TomcatEmbeddedServletContainerFactory” class.
• This “TomcatEmbeddedServletContainerFactory” is used to create an instance of “TomcatEmbeddedServletContainer” class.
• “TomcatEmbeddedServletContainer” instance starts a Tomcat Container at default port number: 8080 and deploys our Spring Boot WebApplication.