DATAMONGO-871 - Add support for arrays as query method return types.

Changed AbstractMongoQuery to potentially convert all query execution results using the DefaultConversionService in case the query result doesn't match the expected return value.

This allows arrays to be returned for collection queries as the conversion service cam transparently convert between collections and arrays.

Author: odrotbohm

spring-data-mongodb/src/main/java/org/springframework/data/mongodb/repository/query/AbstractMongoQuery.java

@@ -82,24 +82,26 @@ public Object execute(Object[] parameters) {
 		MongoParameterAccessor accessor = new MongoParametersParameterAccessor(method, parameters);
 		Query query = createQuery(new ConvertingParameterAccessor(operations.getConverter(), accessor));
 
+		Object result = null;
+
 		if (method.isGeoNearQuery() && method.isPageQuery()) {
 
 			MongoParameterAccessor countAccessor = new MongoParametersParameterAccessor(method, parameters);
 			Query countQuery = createCountQuery(new ConvertingParameterAccessor(operations.getConverter(), countAccessor));
 
-			return new GeoNearExecution(accessor).execute(query, countQuery);
+			result = new GeoNearExecution(accessor).execute(query, countQuery);
 		} else if (method.isGeoNearQuery()) {
-			return new GeoNearExecution(accessor).execute(query);
+			result = new GeoNearExecution(accessor).execute(query);
 		} else if (method.isSliceQuery()) {
-			return new SlicedExecution(accessor.getPageable()).execute(query);
+			result = new SlicedExecution(accessor.getPageable()).execute(query);
 		} else if (method.isCollectionQuery()) {
-			return new CollectionExecution(accessor.getPageable()).execute(query);
+			result = new CollectionExecution(accessor.getPageable()).execute(query);
 		} else if (method.isPageQuery()) {
-			return new PagedExecution(accessor.getPageable()).execute(query);
+			result = new PagedExecution(accessor.getPageable()).execute(query);
+		} else {
+			result = new SingleEntityExecution(isCountQuery()).execute(query);
 		}
 
-		Object result = new SingleEntityExecution(isCountQuery()).execute(query);
-
 		if (result == null) {
 			return result;
 		}

spring-data-mongodb/src/test/java/org/springframework/data/mongodb/repository/AbstractPersonRepositoryIntegrationTests.java

@@ -750,4 +750,16 @@ public void findsSliceOfPersons() {
 
 		assertThat(result.hasNext(), is(true));
 	}
+
+	/**
+	 * @see DATAMONGO-871
+	 */
+	@Test
+	public void findsPersonsByFirstnameAsArray() {
+
+		Person[] result = repository.findByThePersonsFirstnameAsArray("Leroi");
+
+		assertThat(result, is(arrayWithSize(1)));
+		assertThat(result, is(arrayContaining(leroi)));
+	}
 }

spring-data-mongodb/src/test/java/org/springframework/data/mongodb/repository/PersonRepository.java

@@ -71,6 +71,12 @@ public interface PersonRepository extends MongoRepository<Person, String>, Query
 	@Query(value = "{ 'firstname' : ?0 }", fields = "{ 'firstname': 1, 'lastname': 1}")
 	List<Person> findByThePersonsFirstname(String firstname);
 
+	/**
+	 * @see DATAMONGO-871
+	 */
+	@Query(value = "{ 'firstname' : ?0 }")
+	Person[] findByThePersonsFirstnameAsArray(String firstname);
+
 	/**
 	 * Returns all {@link Person}s with a firstname matching the given one (*-wildcard supported).
 	 *