如何使用Spring Boot的Profiles

spring.datasource.driver-class-name=com.mysql.cj.jdbc.Driver
spring.datasource.url=jdbc:mysql://localhost:3306/db
spring.datasource.username=root
spring.datasource.password=root

spring.datasource.driver-class-name=org.h2.Driver
spring.datasource.url=jdbc:h2:mem:db;DB_CLOSE_DELAY=-1
spring.datasource.username=sa
spring.datasource.password=sa

spring.profiles.active=dev

java -jar -Dspring.profiles.active=dev myapp.jar

@Component
@Profile("dev")  //也可以配置成@Profile("!dev")
public class DevDatasourceConfig
..

@SpringBootApplication
public class MyApplication {
    public static void main(String[] args) {
    SpringApplication application = new SpringApplication(MyApplication.class);
    application.setAdditionalProfiles("dev");
    application.run(args);
    }       
}

export spring_profiles_active=dev