DATAMONGO-1291 - Made @Document usable as meta-annotation.

We now use Spring's AnnotationUtils.findAnnotation(…) for @Document lookup which enables the full power of Spring 4.2's composable annotations.

Original pull request: #326.

spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/mapping/BasicMongoPersistentEntity.java

@@ -26,6 +26,7 @@ import org.springframework.context.ApplicationContext;
 import org.springframework.context.ApplicationContextAware;
 import org.springframework.context.expression.BeanFactoryAccessor;
 import org.springframework.context.expression.BeanFactoryResolver;
+import org.springframework.core.annotation.AnnotationUtils;
 import org.springframework.data.annotation.Id;
 import org.springframework.data.mapping.Association;
 import org.springframework.data.mapping.AssociationHandler;
@@ -77,7 +78,7 @@ public class BasicMongoPersistentEntity<T> extends BasicPersistentEntity<T, Mong
 		Class<?> rawType = typeInformation.getType();
 		String fallback = MongoCollectionUtils.getPreferredCollectionName(rawType);
 
-		Document document = rawType.getAnnotation(Document.class);
+		Document document = AnnotationUtils.findAnnotation(rawType, Document.class);
 
 		this.expression = detectExpression(document);
 		this.context = new StandardEvaluationContext();

spring-data-mongodb/src/test/java/org/springframework/data/mongodb/core/mapping/BasicMongoPersistentEntityUnitTests.java

@@ -19,6 +19,11 @@ import static org.hamcrest.CoreMatchers.*;
 import static org.junit.Assert.*;
 import static org.mockito.Mockito.*;
 
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+
 import org.junit.Test;
 import org.junit.runner.RunWith;
 import org.mockito.Mock;
@@ -226,6 +231,18 @@ public class BasicMongoPersistentEntityUnitTests {
 		verify(dbRefMock, times(1)).lazy();
 	}
 
+	/**
+	 * @see DATAMONGO-1291
+	 */
+	@Test
+	public void metaInformationShouldBeReadCorrectlyFromInheritedDocumentAnnotation() {
+
+		BasicMongoPersistentEntity<DocumentWithCustomAnnotation> entity = new BasicMongoPersistentEntity<DocumentWithCustomAnnotation>(
+				ClassTypeInformation.from(DocumentWithCustomAnnotation.class));
+
+		assertThat(entity.getCollection(), is("collection-1"));
+	}
+
 	@Document(collection = "contacts")
 	class Contact {
 
@@ -261,4 +278,15 @@ public class BasicMongoPersistentEntityUnitTests {
 	static class AnyDocument {
 
 	}
+
+	@CustomDocumentAnnotation
+	static class DocumentWithCustomAnnotation {
+
+	}
+
+	@Retention(RetentionPolicy.RUNTIME)
+	@Target({ ElementType.TYPE })
+	@Document(collection = "collection-1")
+	static @interface CustomDocumentAnnotation {
+	}
 }