Profiles

Definition

A profile is a named set of beans or settings for one environment, such as dev or prod. A bean marked @Profile("dev") exists only when the dev profile is active, so one build can behave differently in each environment.

Example code

A different bean for dev and prod

import org.springframework.context.annotation.AnnotationConfigApplicationContext;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.Profile;

interface MailSender { String send(String to); }

@Configuration
class MailConfig {
    @Bean @Profile("dev")
    MailSender fakeSender() { return to -> "DEV: pretend email to " + to; }          // never sends real mail

    @Bean @Profile("prod")
    MailSender realSender() { return to -> "PROD: real email to " + to; }
}

class Demo {
    static void run(String profile) {
        var context = new AnnotationConfigApplicationContext();
        context.getEnvironment().setActiveProfiles(profile);          // in real apps: spring.profiles.active=dev
        context.register(MailConfig.class);
        context.refresh();
        System.out.println(context.getBean(MailSender.class).send("asha@example.com"));
        context.close();
    }

    public static void main(String[] args) {
        run("dev");
        run("prod");
    }
}

// Output:
// DEV: pretend email to asha@example.com
// PROD: real email to asha@example.com