DATAMONGO-1373 - Allow usage of @AliasFor for composed @document annotation.

We now resolve aliased attribute values when reading @document on entity types. This allows creation of composed annotations like:

@retention(RetentionPolicy.RUNTIME)
@target({ ElementType.TYPE })
@document
static @interface ComposedDocumentAnnotation {

  @AliasFor(annotation = Document.class, attribute = "collection")
  String name() default "custom-collection-name";
}

Original pull request: spring-projects#347.
Related issue: DATACMNS-825.

Author: christophstrobl

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

@@ -26,7 +26,6 @@
 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;
@@ -78,7 +77,7 @@ public BasicMongoPersistentEntity(TypeInformation<T> typeInformation) {
 		Class<?> rawType = typeInformation.getType();
 		String fallback = MongoCollectionUtils.getPreferredCollectionName(rawType);
 
-		Document document = AnnotationUtils.findAnnotation(rawType, Document.class);
+		Document document = this.findAnnotation(Document.class);
 
 		this.expression = detectExpression(document);
 		this.context = new StandardEvaluationContext();

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2011-2014 by the original author(s).
+ * Copyright 2011-2016 by the original author(s).
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -29,6 +29,7 @@
 import org.mockito.Mock;
 import org.mockito.runners.MockitoJUnitRunner;
 import org.springframework.context.ApplicationContext;
+import org.springframework.core.annotation.AliasFor;
 import org.springframework.data.mapping.model.MappingException;
 import org.springframework.data.util.ClassTypeInformation;
 
@@ -243,6 +244,18 @@ public void metaInformationShouldBeReadCorrectlyFromInheritedDocumentAnnotation(
 		assertThat(entity.getCollection(), is("collection-1"));
 	}
 
+	/**
+	 * @see DATAMONGO-1373
+	 */
+	@Test
+	public void metaInformationShouldBeReadCorrectlyFromComposedDocumentAnnotation() {
+
+		BasicMongoPersistentEntity<DocumentWithComposedAnnotation> entity = new BasicMongoPersistentEntity<DocumentWithComposedAnnotation>(
+				ClassTypeInformation.from(DocumentWithComposedAnnotation.class));
+
+		assertThat(entity.getCollection(), is("custom-collection"));
+	}
+
 	@Document(collection = "contacts")
 	class Contact {
 
@@ -284,9 +297,23 @@ static class DocumentWithCustomAnnotation {
 
 	}
 
+	@ComposedDocumentAnnotation
+	static class DocumentWithComposedAnnotation {
+
+	}
+
 	@Retention(RetentionPolicy.RUNTIME)
 	@Target({ ElementType.TYPE })
 	@Document(collection = "collection-1")
 	static @interface CustomDocumentAnnotation {
 	}
+
+	@Retention(RetentionPolicy.RUNTIME)
+	@Target({ ElementType.TYPE })
+	@Document
+	static @interface ComposedDocumentAnnotation {
+
+		@AliasFor(annotation = Document.class, attribute = "collection")
+		String name() default "custom-collection";
+	}
 }