[스터디] 스프링 부트 개념과 활용

SpringApplication

https://docs.spring.io/spring-boot/docs/current/reference/htmlsingle/#features.spring-application

Spring Boot Reference Documentation

This section goes into more detail about how you should use Spring Boot. It covers topics such as build systems, auto-configuration, and how to run your applications. We also cover some Spring Boot best practices. Although there is nothing particularly spe

docs.spring.io

- SpringApplication의 기본 log level은 INFO

Springboot Application을 실행하는 3가지 방법

@SpringBootApplication
public class SpringbootApplication {

	/**
	 * 1안) 추가적인 커스터마이징이 불가
	 */
	public static void main(String[] args) {
		SpringApplication.run(SpringbootApplication.class,args);
	}

	/**
	 * 2안) 객체 생성 후 set
	 */
	public static void main(String[] args) {
		final SpringApplication springApplication = new SpringApplication(SpringbootApplication.class);
		springApplication.setWebApplicationType(WebApplicationType.NONE);
		springApplication.run(args);
	}

	/**
	 * 3안) builder를 활용
	 */
	public static void main(String[] args) {
		new SpringApplicationBuilder()
			.sources(SpringbootApplication.class)
			.web(WebApplicationType.NONE)
			.run(args);
	}
}

SpringApplication Event

https://docs.spring.io/spring-boot/docs/current/reference/htmlsingle/#features.spring-application.application-events-and-listeners

Spring Boot Reference Documentation

docs.spring.io

- ApplicationContext가 뜨기 이전의 EventListener들은 Bean으로 등록해도 동작하지 않는다. 그렇기 때문에 아래와 같이 직접 Listener를 등록해주어야 함

@SpringBootApplication
public class SpringbootApplication {

	public static void main(String[] args) {
		final SpringApplication springApplication = new SpringApplication(SpringbootApplication.class);
		springApplication.addListeners(new SampleListener()); //Listener를 직접 등록
		springApplication.setWebApplicationType(WebApplicationType.NONE);
		springApplication.run(args);
	}
}

WebApplicationType

https://docs.spring.io/spring-boot/docs/current/reference/htmlsingle/#features.spring-application.web-environment

Spring Boot Reference Documentation

docs.spring.io

Application Arguments

https://docs.spring.io/spring-boot/docs/current/reference/htmlsingle/#features.spring-application.application-arguments

Spring Boot Reference Documentation

docs.spring.io

VM Options vs Application arguments Options

- -D로 시작하는건 VM

- --로 시작하는건 Application arguments

ApplicationRunner / CommandLineRunner

- SpringApplication이 실행된 후 특정 코드를 한번 수행하고 싶을 때 사용

If you need to run some specific code once the SpringApplication has started, you can implement the
ApplicationRunner or CommandLineRunner interfaces.

https://docs.spring.io/spring-boot/docs/current/reference/htmlsingle/#features.spring-application.command-line-runner

Spring Boot Reference Documentation

docs.spring.io