DATAMONGO-1163 - Allow usage of @indexed as meta-annotation.

@indexed can now be used as meta-annotation so that user annotations can be annotated with it and the index creation facilities still pick up the configuration information.

Original pull request: spring-projects#325.

Author: yacota

spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/index/Indexed.java

@@ -29,8 +29,9 @@
  * @author Johno Crawford
  * @author Thomas Darimont
  * @author Christoph Strobl
+ * @author Jordi Llach
  */
-@Target(ElementType.FIELD)
+@Target({ElementType.ANNOTATION_TYPE, ElementType.FIELD})
 @Retention(RetentionPolicy.RUNTIME)
 public @interface Indexed {
 

spring-data-mongodb/src/test/java/org/springframework/data/mongodb/core/index/IndexingIntegrationTests.java

@@ -15,10 +15,16 @@
  */
 package org.springframework.data.mongodb.core.index;
 
+import com.mongodb.DBCollection;
+import com.mongodb.DBObject;
+import com.mongodb.MongoException;
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
 import static org.hamcrest.CoreMatchers.*;
-import static org.junit.Assert.*;
-
 import org.junit.After;
+import static org.junit.Assert.*;
 import org.junit.Test;
 import org.junit.runner.RunWith;
 import org.springframework.beans.factory.annotation.Autowired;
@@ -30,10 +36,6 @@
 import org.springframework.test.context.ContextConfiguration;
 import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;
 
-import com.mongodb.DBCollection;
-import com.mongodb.DBObject;
-import com.mongodb.MongoException;
-
 /**
  * Integration tests for index handling.
  * 
@@ -45,26 +47,33 @@
 public class IndexingIntegrationTests {
 
 	@Autowired MongoOperations operations;
-
-	@After
+    
+    @After
 	public void tearDown() {
-		operations.dropCollection(IndexedPerson.class);
+        operations.dropCollection(IndexedPerson.class);
 	}
-
-	/**
+   
+    /**
 	 * @see DATADOC-237
+     * @see DATAMONGO-1163
 	 */
 	@Test
 	public void createsIndexWithFieldName() {
-
 		operations.save(new IndexedPerson());
 		assertThat(hasIndex("_firstname", IndexedPerson.class), is(true));
+        assertThat(hasIndex("_lastname", IndexedPerson.class), is(true));
 	}
 
+    @Target({ElementType.FIELD})
+    @Retention(RetentionPolicy.RUNTIME)
+    @Indexed
+    @interface IndexedFieldAnnotation {}
+    
 	@Document
 	class IndexedPerson {
 
 		@Field("_firstname") @Indexed String firstname;
+        @Field("_lastname")  @IndexedFieldAnnotation String lastname;
 	}
 
 	/**
@@ -87,4 +96,4 @@ public Boolean doInCollection(DBCollection collection) throws MongoException, Da
 			}
 		});
 	}
-}
+}

spring-data-mongodb/src/test/java/org/springframework/data/mongodb/core/index/MongoPersistentEntityIndexResolverUnitTests.java

@@ -19,6 +19,10 @@
 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 java.util.Collections;
 import java.util.List;
 
@@ -177,6 +181,19 @@ public void resolvesIndexOnDbrefWhenDefinedOnNestedElement() {
 					equalTo(new BasicDBObjectBuilder().add("nested.indexedDbRef", 1).get()));
 		}
 
+		/**
+		 * @see DATAMONGO-1163
+		 */
+		@Test
+		public void resolveIndexDefinitionInMetaAnnotatedFields() {
+			List<IndexDefinitionHolder> indexDefinitions = prepareMappingContextAndResolveIndexForType(
+					IndexOnMetaAnnotatedField.class);
+			assertThat(indexDefinitions, hasSize(1));
+			assertThat(indexDefinitions.get(0).getCollection(), equalTo("indexOnMetaAnnotatedField"));
+			assertThat(indexDefinitions.get(0).getIndexOptions(),
+					equalTo(new BasicDBObjectBuilder().add("name", "_name").get()));
+		}
+
 		@Document(collection = "Zero")
 		static class IndexOnLevelZero {
 			@Indexed String indexedProperty;
@@ -231,6 +248,18 @@ static class NoIndex {
 
 	}
 
+	@Target({ ElementType.FIELD })
+	@Retention(RetentionPolicy.RUNTIME)
+	@Indexed
+	@interface IndexedFieldAnnotation {
+
+	}
+
+	@Document
+	static class IndexOnMetaAnnotatedField {
+		@Field("_name") @IndexedFieldAnnotation String lastname;
+	}
+
 	/**
 	 * Test resolution of {@link GeoSpatialIndexed}.
 	 *