Environment-based profiles in Spring Boot - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to activate the 'dev' profile in Spring Boot.

Spring Boot

spring.profiles.active=[1]

Drag options to blanks, or click blank then click option'

A"dev"

B"prod"

C"test"

D"default"

Attempts:

3 left

💡 Hint

Common Mistakes

Using quotes incorrectly or missing them.

Setting the profile to a name that does not exist.

To activate the development profile, set spring.profiles.active to "dev".

2fill in blank

medium

Complete the annotation to specify a bean only for the 'prod' profile.

Spring Boot

@Profile([1])
public class ProductionService {}

Drag options to blanks, or click blank then click option'

A"default"

B"test"

C"prod"

D"dev"

Attempts:

3 left

💡 Hint

Common Mistakes

Forgetting quotes around the profile name.

Using the wrong profile name.

The @Profile annotation activates the bean only when the specified profile is active. Here, it should be "prod".

3fill in blank

hard

Complete the YAML to activate the 'test' profile.

Spring Boot

spring:
  profiles: [1]
  datasource:
    url: jdbc:h2:mem:testdb

Drag options to blanks, or click blank then click option'

Ainclude: test

Benabled: test

Cdefault: test

Dactive: test

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'include' or 'enabled' instead of 'active'.

Wrong indentation in YAML.

In YAML, to activate a profile, use spring.profiles.active: test, which is indented as profiles: active: test under spring.

4fill in blank

hard

Fill the blank to define a bean that is active only for 'dev' and 'test' profiles.

Spring Boot

@Profile([1])
public class DevTestService {
  // bean code
}

Drag options to blanks, or click blank then click option'

A"dev & test"

B"dev", "test"

C"dev | test"

D"prod"

Attempts:

3 left

💡 Hint

Common Mistakes

Using '&' or '|' syntax.

Listing profiles without quotes or commas.

Use a comma-separated list like @Profile({"dev", "test"}) to activate for multiple profiles. Multiple values imply OR logic.

5fill in blank

hard

Fill the blanks to create a properties file name for the 'prod' profile with YAML format.

Spring Boot

application-[1].[2]

Drag options to blanks, or click blank then click option'

Aprod

Bproperties

Cyml

Dyaml

Attempts:

3 left

💡 Hint

Common Mistakes

Using '.properties' extension for YAML files.

Misspelling the profile name.

The file name for the production profile in YAML format is application-prod.yml or application-prod.yaml.

Practice

1.

What is the main purpose of using profiles in a Spring Boot application?

easy

A. To separate configuration for different environments like development and production

B. To speed up the application startup time

C. To enable multi-threading in the application

D. To automatically generate database schemas

Solution

1. Step 1: Understand what profiles do

   Profiles allow you to define different settings for different environments, such as development, testing, or production.

2. Step 2: Match purpose with options

   Only To separate configuration for different environments like development and production describes separating configuration for different environments, which is the main use of profiles.

3. Final Answer:

   To separate configuration for different environments like development and production -> Option A

4. Quick Check:

   Profiles = environment-specific settings [OK]

Hint: Profiles separate configs by environment, like dev vs prod [OK]

Common Mistakes:

• Thinking profiles speed up startup
• Confusing profiles with threading
• Assuming profiles auto-generate schemas

2.

Which of the following is the correct way to activate a profile named dev in application.properties?

easy

A. profiles.active=dev

B. spring.profiles.active=dev

C. spring.active.profile=dev

D. spring.profile=dev

Solution

1. Step 1: Recall the correct property key

   The correct property to activate profiles is spring.profiles.active.

2. Step 2: Compare options

   Only spring.profiles.active=dev uses the exact correct key and value format.

3. Final Answer:

   spring.profiles.active=dev -> Option B

4. Quick Check:

   Activate profile with spring.profiles.active [OK]

Hint: Use spring.profiles.active to set active profile [OK]

Common Mistakes:

• Using spring.active.profile instead
• Omitting 'spring' prefix
• Using singular 'profile' instead of 'profiles'

3.

Given the following Spring Boot code snippet, what will be printed if the active profile is prod?

@Component
@Profile("dev")
public class DevService {
    public DevService() {
        System.out.println("DevService active");
    }
}

@Component
@Profile("prod")
public class ProdService {
    public ProdService() {
        System.out.println("ProdService active");
    }
}

medium

A. ProdService active

B. DevService active

C. Both DevService active and ProdService active

D. No output printed

Solution

1. Step 1: Identify active profile

   The active profile is prod, so only beans with @Profile("prod") will be created.

2. Step 2: Determine which constructor runs

   Only ProdService constructor runs, printing "ProdService active".

3. Final Answer:

   ProdService active -> Option A

4. Quick Check:

   @Profile("prod") runs only with prod profile [OK]

Hint: Only beans matching active profile run constructors [OK]

Common Mistakes:

• Assuming both beans run regardless of profile
• Confusing dev and prod profiles
• Thinking no output prints if profile mismatches

4.

Consider this Spring Boot configuration snippet in application.properties:

spring.profiles.active=dev,prod

What is the problem with this configuration?

medium

A. Multiple profiles can be active simultaneously, so no problem

B. Profiles should be separated by semicolon, not comma

C. Activating both dev and prod profiles together can cause conflicts

D. spring.profiles.active cannot be set in application.properties

Solution

1. Step 1: Understand multiple active profiles

   Spring Boot allows multiple profiles active at once, but dev and prod usually have conflicting settings.

2. Step 2: Identify the issue

   Activating both dev and prod together can cause unexpected behavior or conflicts in configuration.

3. Final Answer:

   Activating both dev and prod profiles together can cause conflicts -> Option C

4. Quick Check:

   Dev and prod active together causes config conflicts [OK]

Hint: Avoid activating dev and prod profiles simultaneously [OK]

Common Mistakes:

• Thinking comma separator is invalid
• Believing multiple profiles never cause issues
• Assuming spring.profiles.active can't be set in properties

5.

You want to create a bean that only loads when test profile is active and another bean that loads for all profiles except test. Which annotation setup is correct?

hard

A. @Profile("test") on first bean, no annotation on second bean

B. No need for @Profile, beans load automatically

C. @Profile("test") on first bean, @Profile("prod") on second bean

D. @Profile("test") on first bean, @Profile("!test") on second bean

Solution

1. Step 1: Use @Profile("test") for test-only bean

   This ensures the first bean loads only when the test profile is active.

2. Step 2: Use @Profile("!test") for all except test

   The negation !test means the second bean loads when test is not active.

3. Final Answer:

   @Profile("test") on first bean, @Profile("!test") on second bean -> Option D

4. Quick Check:

   Use @Profile("!profile") to exclude a profile [OK]

Hint: Use @Profile("!test") to exclude test profile [OK]

Common Mistakes:

• Not using @Profile on second bean causes it to always load
• Using @Profile("prod") limits second bean to prod only
• Assuming beans load automatically without profiles