Spring profiles (https://docs.spring.io/spring/docs/current/spring-framework-reference/core.html#beans-definition-profiles-java) let you change the way your application behaves based on environments. This is achieved using the @Profile annotations and profile-specific configuration files, which can be activated by specifying the spring.profiles.active property. Based on the profile that we set here, Spring will choose the appropriate application.properties|application.yml files and will include/exclude components that are included/excluded for the specific profile using the @Profile annotation in the Java source code.

For example, if we set spring.profiles.active=prod, all the Spring components that have @Profile("prod") will be instantiated and any component that has @Profile("!prod") will be excluded. Similarly, Spring will load and use the application-prod.yml or application-prod.properties file if it is available on the classpath.

JHipster configures a dev and prod profile by default, and includes the application-dev.yml and application-prod.yml files in the src/main/resources/config folder, along with the base application.yml file. JHipster goes a step further and provides a dev and a prod profile for the Gradle build as well (also available for Maven) so that we can build/run the application for a particular profile, which is very handy. Here are the profile and database configurations defined in the application-dev.yml file:

...

spring:
    profiles:
        active: dev
        include:
          - swagger
          # Uncomment to activate TLS for the dev profile
          #- tls
    ...
    datasource:
        type: com.zaxxer.hikari.HikariDataSource
        url: jdbc:h2:file:./build/h2db/db/store;DB_CLOSE_DELAY=-1
        username: store
        password:
        hikari:
          poolName: Hikari
          auto-commit: fals
    ...

The following profiles are available in a JHipster application:

Now, let's look at how we can package our application with the production profile.