Spring Boot Study Guide 2026
Everything you need to pass the Spring Boot exam in one place: the exam format, every topic to study, real practice questions with explanations, flashcards, and full-length practice tests. Free, no sign-up needed.
📋 Spring Boot Exam Format at a Glance
📚 Spring Boot Topics to Study (61)
✍️ Sample Spring Boot Questions & Answers
1. How do you implement cross-field validation (e.g., confirming a password matches) using Bean Validation?
Cross-field validation can be done with @ScriptAssert (quick, uses scripting engine) or a custom class-level constraint with a ConstraintValidator that receives the whole object; both are standard approaches.
2. What is the purpose of content negotiation in a Spring REST API?
Content negotiation allows the server to serve different representations (JSON, XML, etc.) of the same resource based on the client's Accept header.
3. Which Spring Boot test slice annotation loads only configuration-related beans for faster tests?
@ConfigurationPropertiesTest loads only ConfigurationProperties beans, making it lightweight for testing property binding.
4. What is the effect of annotating an interface method with @Transactional in Spring?
Spring recommends placing @Transactional on concrete classes rather than interfaces because interface-level annotations are not reliably picked up, especially with class-based (CGLIB) proxies.
5. Which Spring Boot actuator endpoint exposes the resolved configuration properties?
The /actuator/env endpoint shows all property sources and their resolved values, useful for debugging configuration.
6. What property in `application.properties` switches the Spring Boot web application type to reactive?
Setting `spring.main.web-application-type=reactive` forces Spring Boot to start a reactive web environment using WebFlux instead of the servlet stack.