[FIXED] Getting Spring Boot to load annotated resources defined inside runtime dependencies

Issue

I am developing a bunch of Java/Sprint Boot webservices that will all have several identical (ideally, reusable) Spring-based resources:

• many annotation-based Spring Security configurations
• several @Services and @Components
• many annotation-based event handlers
• annotation-based exception handler
  • @ControllerAdvice that extends ResponseEntityExceptionHandler
• annotation-based configuration files (@Configuration)

Ideally I could place these in a library (shared JAR file) and reuse them across the different webservice projects. However I don't believe Spring Boot will scan the entire dependency graph of libraries and load them based on their annotations.

Does anybody know of a way to encourage Spring Boot to do this? For example if I package the following class into a reusable/shareable library JAR:

@ControllerAdvice
@Slf4j
public class ApiExceptionHandler extends ResponseEntityExceptionHandler implements ApiContractConstants {
    // ... common exception handling code to be used by
    // all services
}

And then pull that in to a Spring Boot webservice (via Maven/Gradle) as a runtime dependency, how do I get Spring Boot to scan, find and load that exception handler for me?

Solution

The description makes me think of @SpringBootApplication. The property scanBasePackages of @SpringBootApplication defines base packages to scan for annotated components.

@SpringBootApplication(scanBasePackages = {"org.example"})

Answered By - ViDolf
Answer Checked By - Katrina (JavaFixing Volunteer)