Spring Boot & Auto-Configuration Flashcards

What is the Spring Boot DevTools feature 'LiveReload'?

Answer: Automatically refreshes the browser when classpath resources change

LiveReload is a DevTools feature that triggers a browser refresh when static resources or templates change, improving the development feedback loop.

What is the Spring Boot fat JAR?

Answer: A self-contained executable JAR that includes all dependencies and an embedded server

A Spring Boot fat (uber) JAR packages the application and all its dependencies including the embedded server into a single executable archive.

Which Spring Boot annotation creates a test slice that only loads web layer components?

Answer: @WebMvcTest

@WebMvcTest loads only Spring MVC components (controllers, filters, converters) without starting a full application context, making tests faster.

What does the @ConditionalOnProperty annotation do in Spring Boot auto-configuration?

Answer: Registers a bean only when a specified property has a given value

@ConditionalOnProperty enables or disables bean registration based on whether a configuration property exists and optionally matches a specific value.

What does spring.jpa.hibernate.ddl-auto=update do in Spring Boot?

Answer: Updates the schema to match entities without dropping existing data

The 'update' value instructs Hibernate to modify the existing database schema to match the entity model, adding columns/tables but not removing them.

In Spring Boot, what is an @EventListener?

Answer: An annotation that marks a method to handle application events published in the Spring context

@EventListener marks a method as a handler for application events published via ApplicationEventPublisher, enabling decoupled event-driven communication.