Print Hello World before Spring boot application start - spring

Question

Hello guys I want to ask if its possible to execute the print before the spring boot application start?
import org.springframework.boot.CommandLineRunner;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
#SpringBootApplication
public class SampleApplication implements CommandLineRunner {
public static void main(String[] args) {
SpringApplication.run(SampleApplication.class, args);
}
#Override
public void run(String... args) {
System.out.print("I would be appear in log first before spring application starts");
}
}
My problem of my code it will display the print after the spring boot application start
Current Output
. ____ _ __ _ _
/\\ / ___'_ __ _ _(_)_ __ __ _ \ \ \ \
( ( )\___ | '_ | '_| | '_ \/ _` | \ \ \ \
\\/ ___)| |_)| | | | | || (_| | ) ) ) )
' |____| .__|_| |_|_| |_\__, | / / / /
=========|_|==============|___/=/_/_/_/
:: Spring Boot :: (v2.5.2)
2021-09-26 06:13:53.267 INFO 10352 --- [ main] c.s.d.SampleApplicationTests : Starting SampleApplicationTests using Java 11.0.11 on User-Desktop with PID 10352 (started by ???)
2021-09-26 06:13:53.277 INFO 10352 --- [ main] c.s.d.Sample
ApplicationTests : No active profile set, falling back to default profiles: default
2021-09-26 06:13:54.879 INFO 10352 --- [ main] .s.d.r.c.RepositoryConfigurationDelegate : Bootstrapping Spring Data JPA repositories in DEFAULT mode.
2021-09-26 06:13:55.051 INFO 10352 --- [ main] .s.d.r.c.RepositoryConfigurationDelegate : Finished Spring Data repository scanning in 148 ms. Found 9 JPA repository interfaces.
2021-09-26 06:13:57.118 INFO 10352 --- [ main] o.hibernate.jpa.internal.util.LogHelper : HHH000204: Processing PersistenceUnitInfo [name: default]
2021-09-26 06:13:57.299 INFO 10352 --- [ main] org.hibernate.Version : HHH000412: Hibernate ORM core version 5.4.32.Final
2021-09-26 06:13:57.563 INFO 10352 --- [ main] o.hibernate.annotations.common.Version : HCANN000001: Hibernate Commons Annotations {5.1.2.Final}
2021-09-26 06:13:58.268 INFO 10352 --- [ main] com.zaxxer.hikari.HikariDataSource : HikariPool-1 - Starting...
2021-09-26 06:14:03.062 INFO 10352 --- [ main] com.zaxxer.hikari.HikariDataSource : HikariPool-1 - Start completed.
2021-09-26 06:14:03.094 INFO 10352 --- [ main] org.hibernate.dialect.Dialect : HHH000400: Using dialect: org.hibernate.dialect.MySQLDialect
2021-09-26 06:14:08.430 INFO 10352 --- [ main] o.h.e.t.j.p.i.JtaPlatformInitiator : HHH000490: Using JtaPlatform implementation: [org.hibernate.engine.transaction.jta.platform.internal.NoJtaPlatform]
2021-09-26 06:14:08.453 INFO 10352 --- [ main] j.LocalContainerEntityManagerFactoryBean : Initialized JPA EntityManagerFactory for persistence unit 'default'
2021-09-26 06:14:15.216 INFO 10352 --- [ main] c.s.d.SampleApplicationTests : Started SampleApplicationTests in 22.607 seconds (JVM running for 24.991)
I would be appear in log first before spring application starts

Answer 1

Why don't you just print the log in main method before run invocation?
#SpringBootApplication
public class SampleApplication implements CommandLineRunner {
public static void main(String[] args) {
System.out.print("I would be appear in log first before spring application starts");
SpringApplication.run(SampleApplication.class, args);
}
#Override
public void run(String... args) {
}
}
run method is a method from Spring Boot so everything you do there is done after Spring Boot's start.

Answer 2

If by before the spring boot application start you mean application context startup, then yes, the easiest (for singletons beans, anyway) being to annotate your method with #PostConstruct.
#PostConstruct
public void init() {
//do something
}
Check for the #PostConstruct for e.g here.