From 0b634f83406c044f5317da9c925ad2c74ee3eef2 Mon Sep 17 00:00:00 2001
From: Christoph Strobl <cstrobl@pivotal.io>
Date: Wed, 9 Mar 2016 11:07:07 +0100
Subject: [PATCH] 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: #347.
Related issue: DATACMNS-825.
---
 .../mapping/BasicMongoPersistentEntity.java   |  3 +-
 .../BasicMongoPersistentEntityUnitTests.java  | 29 ++++++++++++++++++-
 2 files changed, 29 insertions(+), 3 deletions(-)

diff --git a/spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/mapping/BasicMongoPersistentEntity.java b/spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/mapping/BasicMongoPersistentEntity.java
index d182a9460..a1196fca4 100644
--- a/spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/mapping/BasicMongoPersistentEntity.java
+++ b/spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/mapping/BasicMongoPersistentEntity.java
@@ -26,7 +26,6 @@ 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;
@@ -78,7 +77,7 @@ public class BasicMongoPersistentEntity<T> extends BasicPersistentEntity<T, Mong
 		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();
diff --git a/spring-data-mongodb/src/test/java/org/springframework/data/mongodb/core/mapping/BasicMongoPersistentEntityUnitTests.java b/spring-data-mongodb/src/test/java/org/springframework/data/mongodb/core/mapping/BasicMongoPersistentEntityUnitTests.java
index a420c24d8..458b0fd4b 100644
--- a/spring-data-mongodb/src/test/java/org/springframework/data/mongodb/core/mapping/BasicMongoPersistentEntityUnitTests.java
+++ b/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.junit.runner.RunWith;
 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 class BasicMongoPersistentEntityUnitTests {
 		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 @@ public class BasicMongoPersistentEntityUnitTests {
 
 	}
 
+	@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";
+	}
 }