Profile-based configuration in Spring Boot - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is profile-based configuration in Spring Boot?

It is a way to define different settings for different environments (like development, testing, production) so the app behaves correctly in each.

beginner

How do you activate a Spring Boot profile?

You can activate a profile by setting the property spring.profiles.active in application.properties or by passing --spring.profiles.active=profileName as a command line argument.

beginner

What file naming convention does Spring Boot use for profile-specific properties?

Spring Boot uses application-{profile}.properties or application-{profile}.yml where {profile} is the profile name, like application-dev.properties.

intermediate

Can multiple profiles be active at the same time in Spring Boot?

Yes, you can activate multiple profiles by separating them with commas, like spring.profiles.active=dev,debug. Settings from all active profiles are combined.

beginner

Why is profile-based configuration useful in real projects?

It helps keep environment-specific settings separate, so you don’t mix development settings with production ones. This reduces errors and makes deployment safer.

Which file would Spring Boot load if the active profile is 'test'?

A application-test.properties

B application.properties

C application-prod.properties

D application-default.properties

Spring Boot loads the profile-specific file named with the active profile, like application-test.properties.

How do you specify the active profile when running a Spring Boot app from the command line?

A --spring.profiles.active=profileName

B --profile=profileName

C spring.active=profileName

D profile.active=profileName

The correct syntax is --spring.profiles.active=profileName to activate a profile.

If no profile is active, which configuration file does Spring Boot use?

A No configuration file is loaded

B application-default.properties

C application-prod.properties

D application.properties

Spring Boot uses application.properties as the default configuration file when no profile is active.

Can you combine settings from multiple active profiles?

A No, profiles override each other completely

B Yes, Spring Boot merges settings from all active profiles

C Yes, but only the first profile’s settings are used

D No, only one profile can be active at a time

Spring Boot merges settings from all active profiles, allowing combined configuration.

What is the main benefit of using profile-based configuration?

A Make the app run faster

B Reduce the size of the app

C Separate environment settings to avoid mistakes

D Automatically fix bugs

Profile-based configuration helps keep environment-specific settings separate, reducing errors.

Explain how to set up and use profile-based configuration in a Spring Boot project.

Think about how you tell Spring Boot which environment to use and where you put the settings.

Describe why profile-based configuration is important for deploying applications safely.

Consider what could go wrong if all settings were mixed together.