Spring Profiles (@Profile, spring.profiles.active)

Spring profiles let you register different bean graphs and load different property files based on the active environment — without changing code or rebuilding the artifact. The same JAR behaves differently in dev, staging, and production based on which profiles are active.

Profile-specific beans

• @Profile("prod") on a @Bean or @Configuration class — only registered when prod is active
• @Profile("!prod") — registered in every profile except production; common for debug tooling and mock services
• Multiple active profiles at once: spring.profiles.active=prod,monitoring — beans from both profiles are registered

Activating profiles — priority order

• Command-line --spring.profiles.active=prod — highest priority, overrides everything else
• Environment variable SPRING_PROFILES_ACTIVE=prod — Docker and Kubernetes standard
• spring.profiles.active=dev in application.properties — developer default, lowest priority

Profile-specific property files

• application-prod.properties loads automatically when prod is active and overrides the base application.properties for any key present in both
• Base file sets defaults; profile files override what is environment-specific

Profile groups (Spring Boot 2.4+)

• spring.profiles.group.production=prod,monitoring,security — activate production and all three sub-profiles activate automatically

In tests, @ActiveProfiles("test") loads application-test.properties — typically with an H2 in-memory database, mock service URLs, and verbose logging. Tests never accidentally hit production resources.