Spring Framework Research & Evidence-Based Practice 4

Question 1

Which Spring Boot feature allows developers to observe actual auto-configuration decisions made at startup, providing evidence for why a bean was or was not created?

Accepted Answer

ConditionEvaluationReport via /actuator/conditions or --debug flag

Answer

The ConditionEvaluationReport, accessible via the /actuator/conditions endpoint or the --debug startup flag, documents exactly which auto-configuration conditions matched or failed.

Question 2

When evaluating Spring Data query performance, which approach provides concrete evidence of the SQL generated by a derived query method?

Accepted Answer

Setting spring.jpa.show-sql=true and logging the output

Answer

Setting spring.jpa.show-sql=true (or enabling Hibernate SQL logging) logs the actual SQL statements, giving direct evidence of what queries Spring Data generates.

Question 3

A Spring Boot application suffers from slow startup in production. Which evidence-based tool does Spring provide specifically to diagnose startup performance?

Accepted Answer

Spring Boot Actuator /startup endpoint with ApplicationStartup

Answer

Spring Boot's ApplicationStartup API, combined with the /actuator/startup endpoint, records timestamped steps during context initialization to pinpoint slow startup contributors.

Question 4

What is the recommended evidence-based approach for verifying that Spring Cache (@Cacheable) is actually caching method results and not calling the underlying method twice?

Accepted Answer

Use a spy or mock to count invocations and assert the method was called only once on repeated calls

Answer

Using Mockito.spy() or a counter in the real implementation and asserting the method is invoked only once on the second call provides concrete, measurable evidence that caching is working.

Question 5

Spring's documented 'fail-fast' principle recommends which behavior when required configuration properties are missing at startup?

Accepted Answer

Throw a startup exception before the application accepts traffic

Answer

The fail-fast principle, implemented via @ConfigurationProperties validation with @NotNull/@NotEmpty, causes Spring Boot to throw a BindException at startup, preventing a misconfigured app from serving traffic.

Spring Framework Practice Test

Spring Framework Practice Test

Spring Framework Research & Evidence-Based Practice 4