DATACMNS-1596 - Modules not exposing identifying annotations do not claim repository interfaces anymore.

Previously, a module not exposing any entity identifying annotations would have claimed a repository definition and potentially overrode the bean definition of another store that was the proper claim in the first place. We have now changed this to abstain from a claim of the interface.

We' also tweaked the log output in the following cases:

1. If the module neither returns an identifying type nor entity identifying annotations, we now log a warning that a module does not support a multi-module setup and answer all assignment requests with false.

2. The info level warning indicating an interface has been dropped now reports which annotations or interface base types to use.

Related tickets: spring-projects/spring-boot#18721

Author: odrotbohm

src/main/java/org/springframework/data/repository/config/RepositoryConfigurationExtensionSupport.java

@@ -23,6 +23,7 @@
 import java.util.HashSet;
 import java.util.Set;
 import java.util.function.Supplier;
+import java.util.stream.Collectors;
 
 import javax.annotation.Nullable;
 
@@ -53,7 +54,9 @@ public abstract class RepositoryConfigurationExtensionSupport implements Reposit
 
 	private static final Logger LOGGER = LoggerFactory.getLogger(RepositoryConfigurationExtensionSupport.class);
 	private static final String CLASS_LOADING_ERROR = "%s - Could not load type %s using class loader %s.";
-	private static final String MULTI_STORE_DROPPED = "Spring Data {} - Could not safely identify store assignment for repository candidate {}.";
+	private static final String MULTI_STORE_DROPPED = "Spring Data %s - Could not safely identify store assignment for repository candidate %s. If you want this repository to be a %s repository,";
+
+	private boolean noMultiStoreSupport = false;
 
 	/*
 	 * (non-Javadoc)
@@ -294,7 +297,22 @@ protected <T extends RepositoryConfigurationSource> RepositoryConfiguration<T> g
 	 */
 	protected boolean isStrictRepositoryCandidate(RepositoryMetadata metadata) {
 
+		if (noMultiStoreSupport) {
+			return false;
+		}
+
 		Collection<Class<?>> types = getIdentifyingTypes();
+		Collection<Class<? extends Annotation>> annotations = getIdentifyingAnnotations();
+		String moduleName = getModuleName();
+
+		if (types.isEmpty() && annotations.isEmpty()) {
+			if (!noMultiStoreSupport) {
+				LOGGER.warn("Spring Data {} does not support multi-store setups!", moduleName);
+				noMultiStoreSupport = true;
+				return false;
+			}
+		}
+
 		Class<?> repositoryInterface = metadata.getRepositoryInterface();
 
 		for (Class<?> type : types) {
@@ -304,19 +322,30 @@ protected boolean isStrictRepositoryCandidate(RepositoryMetadata metadata) {
 		}
 
 		Class<?> domainType = metadata.getDomainType();
-		Collection<Class<? extends Annotation>> annotations = getIdentifyingAnnotations();
-
-		if (annotations.isEmpty()) {
-			return true;
-		}
 
 		for (Class<? extends Annotation> annotationType : annotations) {
 			if (AnnotationUtils.findAnnotation(domainType, annotationType) != null) {
 				return true;
 			}
 		}
 
-		LOGGER.info(MULTI_STORE_DROPPED, getModuleName(), repositoryInterface);
+		String message = String.format(MULTI_STORE_DROPPED, moduleName, repositoryInterface, moduleName);
+
+		if (!annotations.isEmpty()) {
+			message = message.concat(" consider annotating your entities with one of these annotations: ") //
+					.concat(toString(annotations)) //
+					.concat(types.isEmpty() ? "." : " (preferred)");
+		}
+
+		if (!types.isEmpty()) {
+
+			message = message.concat(annotations.isEmpty() ? " consider" : ", or consider") //
+					.concat(" extending one of the following types with your repository: ") //
+					.concat(toString(types)) //
+					.concat(".");
+		}
+
+		LOGGER.info(message);
 
 		return false;
 	}
@@ -364,4 +393,11 @@ private Class<?> loadRepositoryInterface(RepositoryConfiguration<?> configuratio
 
 		return null;
 	}
+
+	private static String toString(Collection<? extends Class<?>> types) {
+
+		return types.stream() //
+				.map(Class::getName) //
+				.collect(Collectors.joining(", "));
+	}
 }

src/test/java/org/springframework/data/repository/config/RepositoryConfigurationExtensionSupportUnitTests.java

@@ -34,9 +34,11 @@
 import org.springframework.core.type.AnnotationMetadata;
 import org.springframework.core.type.StandardAnnotationMetadata;
 import org.springframework.dao.InvalidDataAccessApiUsageException;
+import org.springframework.data.repository.CrudRepository;
 import org.springframework.data.repository.Repository;
 import org.springframework.data.repository.core.RepositoryMetadata;
 import org.springframework.data.repository.core.support.AbstractRepositoryMetadata;
+import org.springframework.data.repository.core.support.RepositoryFactoryBeanSupport;
 import org.springframework.data.repository.core.support.RepositoryFactorySupport;
 import org.springframework.data.repository.reactive.ReactiveCrudRepository;
 
@@ -86,6 +88,15 @@ public void rejectsReactiveRepositories() {
 				.hasMessageContaining("Reactive Repositories are not supported");
 	}
 
+	@Test // DATACMNS-1596
+	public void doesNotClaimEntityIfNoIdentifyingAnnotationsAreExposed() {
+
+		NonIdentifyingConfigurationExtension extension = new NonIdentifyingConfigurationExtension();
+		RepositoryMetadata metadata = AbstractRepositoryMetadata.getMetadata(AnnotatedTypeRepository.class);
+
+		assertThat(extension.isStrictRepositoryCandidate(metadata)).isFalse();
+	}
+
 	static class SampleRepositoryConfigurationExtension extends RepositoryConfigurationExtensionSupport {
 
 		@Override
@@ -109,6 +120,24 @@ protected Collection<Class<?>> getIdentifyingTypes() {
 		}
 	}
 
+	static class NonIdentifyingConfigurationExtension extends RepositoryConfigurationExtensionSupport {
+
+		@Override
+		protected String getModulePrefix() {
+			return "non-identifying";
+		}
+
+		@Override
+		public String getRepositoryFactoryBeanClassName() {
+			return RepositoryFactoryBeanSupport.class.getName();
+		}
+
+		@Override
+		protected Collection<Class<?>> getIdentifyingTypes() {
+			return Collections.singleton(CrudRepository.class);
+		}
+	}
+
 	@Primary
 	static class AnnotatedType {}