The profile annotation can be used when you have multiple implementations of the same bean which might be injected depending of the activated profile in the application.

Profiles can be used at:

  • @Component level
  • @Configuration level
  • @Bean method level

Declaring a profile

One simple example is imagine that you have a Repository like below and 2 implementations one for file and another for database


public interface ItemRepository{ 
  
    void save(Item item);
}


@Repository
@Profile("file")
public class FileItemRepository{
    void save(Item item){
     System.out.println("Saving in the filesystem");
   }       
  
}


@Repository
@Profile("database")
public class DatabaseItemRepository{
    void save(Item item){
     System.out.println("Saving in database");
   }       
  
}

Note tha you can also use negation sign (!) if you want to specify for example only if profile not database = !database

Activating a profile

A profile can be activated in several ways

Programmatically

While starting up your standalone context you can call setActiveProfiles

    
        AnnotationConfigApplicationContext context = new AnnotationConfigApplicationContext();
        // Activate profile
        context.getEnvironment().setActiveProfiles("file");

or using Spring Boot like the example below:


    public static void main(String[] args) {
        new SpringApplicationBuilder(Runner.class)
                .profiles("database")
                .run(args);
    }

Vm properties

You can also use VM properties to activate it like

-Dspring.profiles.active=database

JUnit tests

You can activate your profiles in a JUnit test using the following annotation @ActiveProfiles


@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration(classes = ApplicationConfig.class)
@ActiveProfiles("database")
public class ApplicationTest {
   
}