DATACMNS-825 - Allow usage of composed annotations using @AliasFor.

We now resolve composed annotation values using @AliasFor within AnnotationBasedPersistentProperty and BasicPersistentEntity. Nevertheless it is up to the individual store implementation to make use of this.

Original pull request: #156.

Author: christophstrobl

src/main/java/org/springframework/data/mapping/model/AnnotationBasedPersistentProperty.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2011-2014 the original author or authors.
+ * Copyright 2011-2016 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -25,7 +25,7 @@
 
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.beans.factory.annotation.Value;
-import org.springframework.core.annotation.AnnotationUtils;
+import org.springframework.core.annotation.AnnotatedElementUtils;
 import org.springframework.data.annotation.AccessType;
 import org.springframework.data.annotation.AccessType.Type;
 import org.springframework.data.annotation.Id;
@@ -223,14 +223,15 @@ public <A extends Annotation> A findAnnotation(Class<A> annotationType) {
 				continue;
 			}
 
-			A annotation = AnnotationUtils.findAnnotation(method, annotationType);
+			A annotation = AnnotatedElementUtils.findMergedAnnotation(method, annotationType);
 
 			if (annotation != null) {
 				return cacheAndReturn(annotationType, annotation);
 			}
 		}
 
-		return cacheAndReturn(annotationType, field == null ? null : AnnotationUtils.getAnnotation(field, annotationType));
+		return cacheAndReturn(annotationType,
+				field == null ? null : AnnotatedElementUtils.findMergedAnnotation(field, annotationType));
 	}
 
 	/* 

src/main/java/org/springframework/data/mapping/model/BasicPersistentEntity.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2011-2015 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.
@@ -27,7 +27,7 @@
 import java.util.Set;
 import java.util.TreeSet;
 
-import org.springframework.core.annotation.AnnotationUtils;
+import org.springframework.core.annotation.AnnotatedElementUtils;
 import org.springframework.data.annotation.TypeAlias;
 import org.springframework.data.mapping.Association;
 import org.springframework.data.mapping.AssociationHandler;
@@ -50,6 +50,7 @@
  * @author Jon Brisbin
  * @author Patryk Wasik
  * @author Thomas Darimont
+ * @author Christoph Strobl
  */
 public class BasicPersistentEntity<T, P extends PersistentProperty<P>> implements MutablePersistentEntity<T, P> {
 
@@ -284,7 +285,7 @@ public Class<T> getType() {
 	 */
 	public Object getTypeAlias() {
 
-		TypeAlias alias = getType().getAnnotation(TypeAlias.class);
+		TypeAlias alias = AnnotatedElementUtils.findMergedAnnotation(getType(), TypeAlias.class);
 		return alias == null ? null : StringUtils.hasText(alias.value()) ? alias.value() : null;
 	}
 
@@ -366,7 +367,7 @@ public <A extends Annotation> A findAnnotation(Class<A> annotationType) {
 			return annotation;
 		}
 
-		annotation = AnnotationUtils.findAnnotation(getType(), annotationType);
+		annotation = AnnotatedElementUtils.findMergedAnnotation(getType(), annotationType);
 		annotationCache.put(annotationType, annotation);
 
 		return annotation;

src/main/java/org/springframework/data/util/AnnotationDetectionFieldCallback.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2014 the original author or authors.
+ * Copyright 2012-2016 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -18,6 +18,7 @@
 import java.lang.annotation.Annotation;
 import java.lang.reflect.Field;
 
+import org.springframework.core.annotation.AnnotatedElementUtils;
 import org.springframework.util.Assert;
 import org.springframework.util.ReflectionUtils;
 import org.springframework.util.ReflectionUtils.FieldCallback;
@@ -27,6 +28,7 @@
  * afterwards.
  * 
  * @author Oliver Gierke
+ * @author Christoph Strobl
  */
 public class AnnotationDetectionFieldCallback implements FieldCallback {
 
@@ -54,7 +56,7 @@ public void doWith(Field field) throws IllegalArgumentException, IllegalAccessEx
 			return;
 		}
 
-		Annotation annotation = field.getAnnotation(annotationType);
+		Annotation annotation = AnnotatedElementUtils.findMergedAnnotation(field, annotationType);
 
 		if (annotation != null) {
 

src/main/java/org/springframework/data/util/AnnotationDetectionMethodCallback.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2014 the original author or authors.
+ * Copyright 2014-2016 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -18,14 +18,15 @@
 import java.lang.annotation.Annotation;
 import java.lang.reflect.Method;
 
-import org.springframework.core.annotation.AnnotationUtils;
+import org.springframework.core.annotation.AnnotatedElementUtils;
 import org.springframework.util.Assert;
 import org.springframework.util.ReflectionUtils.MethodCallback;
 
 /**
  * {@link MethodCallback} to find annotations of a given type.
  * 
  * @author Oliver Gierke
+ * @author Christoph Strobl
  */
 public class AnnotationDetectionMethodCallback<A extends Annotation> implements MethodCallback {
 
@@ -94,7 +95,7 @@ public void doWith(Method method) throws IllegalArgumentException, IllegalAccess
 			return;
 		}
 
-		A foundAnnotation = AnnotationUtils.findAnnotation(method, annotationType);
+		A foundAnnotation = AnnotatedElementUtils.findMergedAnnotation(method, annotationType);
 
 		if (foundAnnotation != null) {
 

src/test/java/org/springframework/data/mapping/model/AnnotationBasedPersistentPropertyUnitTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2013-2014 the original author or authors.
+ * Copyright 2013-2016 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -29,6 +29,8 @@
 
 import org.junit.Before;
 import org.junit.Test;
+import org.springframework.core.annotation.AliasFor;
+import org.springframework.core.annotation.AnnotationUtils;
 import org.springframework.data.annotation.AccessType;
 import org.springframework.data.annotation.AccessType.Type;
 import org.springframework.data.annotation.Id;
@@ -220,6 +222,37 @@ public void cachesNonPresenceOfAnnotationOnField() {
 		assertThat(field.get(MyAnnotation.class), is(nullValue()));
 	}
 
+	/**
+	 * @see DATACMNS-825
+	 */
+	@Test
+	public void composedAnnotationWithAliasForGetCachedCorrectly() {
+
+		SamplePersistentProperty property = entity.getPersistentProperty("metaAliased");
+
+		// Assert direct annotations are cached on construction
+		Map<Class<? extends Annotation>, Annotation> cache = getAnnotationCache(property);
+		assertThat(cache.containsKey(MyComposedAnnotationUsingAliasFor.class), is(true));
+		assertThat(cache.containsKey(MyAnnotation.class), is(false));
+
+		// Assert meta annotation is found and cached
+		MyAnnotation annotation = property.findAnnotation(MyAnnotation.class);
+		assertThat(annotation, is(notNullValue()));
+		assertThat(cache.containsKey(MyAnnotation.class), is(true));
+	}
+
+	/**
+	 * @see DATACMNS-825
+	 */
+	@Test
+	public void composedAnnotationWithAliasShouldHaveSynthesizedAttributeValues() {
+
+		SamplePersistentProperty property = entity.getPersistentProperty("metaAliased");
+
+		MyAnnotation annotation = property.findAnnotation(MyAnnotation.class);
+		assertThat(AnnotationUtils.getValue(annotation), is((Object) "spring"));
+	}
+
 	@SuppressWarnings("unchecked")
 	private Map<Class<? extends Annotation>, Annotation> getAnnotationCache(SamplePersistentProperty property) {
 		return (Map<Class<? extends Annotation>, Annotation>) ReflectionTestUtils.getField(property, "annotationCache");
@@ -248,6 +281,8 @@ static class Sample {
 
 		@MyAnnotationAsMeta String meta;
 
+		@MyComposedAnnotationUsingAliasFor String metaAliased;
+
 		@MyAnnotation
 		public String getGetter() {
 			return getter;
@@ -314,6 +349,15 @@ public String getProperty() {
 
 	}
 
+	@Retention(RetentionPolicy.RUNTIME)
+	@Target(value = { FIELD, METHOD })
+	@MyAnnotation
+	public static @interface MyComposedAnnotationUsingAliasFor {
+
+		@AliasFor(annotation = MyAnnotation.class, attribute = "value")
+		String name() default "spring";
+	}
+
 	@Retention(RetentionPolicy.RUNTIME)
 	@Target(value = { FIELD, METHOD, ANNOTATION_TYPE })
 	@Id

src/test/java/org/springframework/data/mapping/model/BasicPersistentEntityUnitTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2011-2015 the original author or authors.
+ * Copyright 2011-2016 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -19,6 +19,8 @@
 import static org.junit.Assert.*;
 import static org.mockito.Mockito.*;
 
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
 import java.util.Comparator;
 import java.util.Iterator;
 import java.util.List;
@@ -30,6 +32,7 @@
 import org.mockito.Mock;
 import org.mockito.Mockito;
 import org.mockito.runners.MockitoJUnitRunner;
+import org.springframework.core.annotation.AliasFor;
 import org.springframework.data.annotation.CreatedBy;
 import org.springframework.data.annotation.CreatedDate;
 import org.springframework.data.annotation.LastModifiedBy;
@@ -224,6 +227,17 @@ public void supportsSubtypeInstancesOnPropertyAccessorLookup() {
 		assertThat(entity.getPropertyAccessor(new Subtype()), is(notNullValue()));
 	}
 
+	/**
+	 * @see DATACMNS-825
+	 */
+	@Test
+	public void returnsTypeAliasIfAnnotatedUsingComposedAnnotation() {
+
+		PersistentEntity<AliasEntityUsingComposedAnnotation, T> entity = createEntity(
+				AliasEntityUsingComposedAnnotation.class);
+		assertThat(entity.getTypeAlias(), is((Object) "bar"));
+	}
+
 	private <S> BasicPersistentEntity<S, T> createEntity(Class<S> type) {
 		return createEntity(type, null);
 	}
@@ -251,5 +265,18 @@ public String getProperty() {
 		}
 	}
 
+	@Retention(RetentionPolicy.RUNTIME)
+	@TypeAlias("foo")
+	static @interface ComposedTypeAlias {
+
+		@AliasFor(annotation = TypeAlias.class, attribute = "value")
+		String name() default "bar";
+	}
+
+	@ComposedTypeAlias
+	static class AliasEntityUsingComposedAnnotation {
+
+	}
+
 	static class Subtype extends Entity {}
 }