DATAJDBC-182 - Polishing.

Extracted method to maintain a single level of abstraction.
Added description to assertion that wasn't obvious to me.
Added JavaDoc on existing method.
Commented repository methods in test with issue ids to ease understanding the purpose of each method.

src/main/java/org/springframework/data/jdbc/repository/support/JdbcQueryLookupStrategy.java

@@ -56,18 +56,21 @@ class JdbcQueryLookupStrategy implements QueryLookupStrategy {
 
 		JdbcQueryMethod queryMethod = new JdbcQueryMethod(method, repositoryMetadata, projectionFactory);
 		Class<?> returnedObjectType = queryMethod.getReturnedObjectType();
-		RowMapper<?> rowMapper = null;
+
-		if (!queryMethod.isModifyingQuery()) {
+		RowMapper<?> rowMapper = queryMethod.isModifyingQuery() ? null : createRowMapper(returnedObjectType);
-			rowMapper = context.getSimpleTypeHolder().isSimpleType(returnedObjectType)
+
-					? SingleColumnRowMapper.newInstance(returnedObjectType, conversionService)
-					: new EntityRowMapper<>( //
-							context.getRequiredPersistentEntity(returnedObjectType), //
-							conversionService, //
-							context, //
-							accessStrategy //
-					);
-		}
 		return new JdbcRepositoryQuery(queryMethod, context, rowMapper);
 	}
 
+	private RowMapper<?> createRowMapper(Class<?> returnedObjectType) {
+
+		return context.getSimpleTypeHolder().isSimpleType(returnedObjectType)
+				? SingleColumnRowMapper.newInstance(returnedObjectType, conversionService)
+				: new EntityRowMapper<>( //
+						context.getRequiredPersistentEntity(returnedObjectType), //
+						conversionService, //
+						context, //
+						accessStrategy //
+				);
+	}
 }

src/main/java/org/springframework/data/jdbc/repository/support/JdbcQueryMethod.java

@@ -24,6 +24,7 @@ import org.springframework.data.jdbc.repository.query.Query;
 import org.springframework.data.projection.ProjectionFactory;
 import org.springframework.data.repository.core.RepositoryMetadata;
 import org.springframework.data.repository.query.QueryMethod;
+import org.springframework.lang.Nullable;
 
 /**
  * {@link QueryMethod} implementation that implements a method by executing the query from a {@link Query} annotation on
@@ -44,6 +45,12 @@ public class JdbcQueryMethod extends QueryMethod {
 		this.method = method;
 	}
 
+	/**
+	 * Returns the annotated query if it exists.
+	 *
+	 * @return May be {@code null}.
+	 */
+	@Nullable
 	public String getAnnotatedQuery() {
 
 		Query queryAnnotation = AnnotatedElementUtils.findMergedAnnotation(method, Query.class);

src/test/java/org/springframework/data/jdbc/repository/query/QueryAnnotationHsqlIntegrationTests.java

@@ -15,6 +15,14 @@
  */
 package org.springframework.data.jdbc.repository.query;
 
+import static org.assertj.core.api.Assertions.*;
+
+import java.time.LocalDateTime;
+import java.util.Date;
+import java.util.List;
+import java.util.Optional;
+import java.util.stream.Stream;
+
 import org.junit.ClassRule;
 import org.junit.Rule;
 import org.junit.Test;
@@ -33,14 +41,6 @@ import org.springframework.test.context.junit4.rules.SpringClassRule;
 import org.springframework.test.context.junit4.rules.SpringMethodRule;
 import org.springframework.transaction.annotation.Transactional;
 
-import java.time.LocalDateTime;
-import java.util.Date;
-import java.util.List;
-import java.util.Optional;
-import java.util.stream.Stream;
-
-import static org.assertj.core.api.Assertions.*;
-
 /**
  * Tests the execution of queries from {@link Query} annotations on repository methods.
  *
@@ -51,13 +51,10 @@ import static org.assertj.core.api.Assertions.*;
 @Transactional
 public class QueryAnnotationHsqlIntegrationTests {
 
-	@Autowired
+	@Autowired DummyEntityRepository repository;
-	DummyEntityRepository repository;
 
-	@ClassRule
+	@ClassRule public static final SpringClassRule classRule = new SpringClassRule();
-	public static final SpringClassRule classRule = new SpringClassRule();
+	@Rule public SpringMethodRule methodRule = new SpringMethodRule();
-	@Rule
-	public SpringMethodRule methodRule = new SpringMethodRule();
 
 	@Test // DATAJDBC-164
 	public void executeCustomQueryWithoutParameter() {
@@ -167,7 +164,7 @@ public class QueryAnnotationHsqlIntegrationTests {
 				.containsExactlyInAnyOrder("a", "b");
 
 	}
-	
+
 	@Test // DATAJDBC-175
 	public void executeCustomQueryWithReturnTypeIsNubmer() {
 
@@ -211,36 +208,40 @@ public class QueryAnnotationHsqlIntegrationTests {
 	}
 
 	@Test // DATAJDBC-182
-	public void executeCustomModifyingQueryWithReturnTypeIsNumber() {
+	public void executeCustomModifyingQueryWithReturnTypeNumber() {
 
 		DummyEntity entity = dummyEntity("a");
 		repository.save(entity);
 
 		assertThat(repository.updateName(entity.id, "b")).isEqualTo(1);
-		assertThat(repository.updateName(9999L, "b")).isEqualTo(0);
+		assertThat(repository.updateName(9999L, "c")).isEqualTo(0);
-		assertThat(repository.findById(entity.id)).isPresent().map(e -> e.name).contains("b");
 
+		assertThat(repository.findById(entity.id)) //
+				.describedAs("update was not performed as expected") //
+				.isPresent() //
+				.map(e -> e.name).contains("b");
 	}
 
 	@Test // DATAJDBC-182
-	public void executeCustomModifyingQueryWithReturnTypeIsBoolean() {
+	public void executeCustomModifyingQueryWithReturnTypeBoolean() {
 
 		DummyEntity entity = dummyEntity("a");
 		repository.save(entity);
 
 		assertThat(repository.deleteByName("a")).isTrue();
 		assertThat(repository.deleteByName("b")).isFalse();
-		assertThat(repository.findById(entity.id)).isNotPresent();
 
+		assertThat(repository.findById(entity.id)) //
+				.describedAs("delete not performed as expected") //
+				.isNotPresent();
 	}
 
 	@Test // DATAJDBC-182
-	public void executeCustomModifyingQueryWithReturnTypeIsVoid() {
+	public void executeCustomModifyingQueryWithReturnTypeVoid() {
 
 		repository.insert("Spring Data JDBC");
 
 		assertThat(repository.findByNameAsEntity("Spring Data JDBC")).isNotNull();
-
 	}
 
 	private DummyEntity dummyEntity(String name) {
@@ -263,49 +264,59 @@ public class QueryAnnotationHsqlIntegrationTests {
 
 	private static class DummyEntity {
 
-		@Id
+		@Id Long id;
-		Long id;
 
 		String name;
 	}
 
 	private interface DummyEntityRepository extends CrudRepository<DummyEntity, Long> {
 
+		// DATAJDBC-164
 		@Query("SELECT * FROM DUMMYENTITY WHERE lower(name) <> name")
 		List<DummyEntity> findByNameContainingCapitalLetter();
 
+		// DATAJDBC-164
 		@Query("SELECT * FROM DUMMYENTITY WHERE name  < :upper and name > :lower")
 		List<DummyEntity> findByNamedRangeWithNamedParameter(@Param("lower") String lower, @Param("upper") String upper);
 
 		@Query("SELECT * FROM DUMMYENTITY WHERE name = :name")
 		Optional<DummyEntity> findByNameAsOptional(@Param("name") String name);
 
+		// DATAJDBC-172
 		@Query("SELECT * FROM DUMMYENTITY WHERE name = :name")
 		DummyEntity findByNameAsEntity(@Param("name") String name);
 
+		// DATAJDBC-172
 		@Query("SELECT * FROM DUMMYENTITY")
 		Stream<DummyEntity> findAllWithReturnTypeIsStream();
 
+		// DATAJDBC-175
 		@Query("SELECT count(*) FROM DUMMYENTITY WHERE name like '%' || :name || '%'")
 		int countByNameContaining(@Param("name") String name);
 
+		// DATAJDBC-175
 		@Query("SELECT count(*) FROM DUMMYENTITY WHERE name like '%' || :name || '%'")
 		boolean existsByNameContaining(@Param("name") String name);
 
+		// DATAJDBC-175
 		@Query("VALUES (current_timestamp)")
 		Date nowWithDate();
 
+		// DATAJDBC-175
 		@Query("VALUES (current_timestamp),(current_timestamp)")
 		List<LocalDateTime> nowWithLocalDateTimeList();
 
+		// DATAJDBC-182
 		@Modifying
 		@Query("UPDATE DUMMYENTITY SET name = :name WHERE id = :id")
 		int updateName(@Param("id") Long id, @Param("name") String name);
 
+		// DATAJDBC-182
 		@Modifying
 		@Query("DELETE FROM DUMMYENTITY WHERE name = :name")
 		boolean deleteByName(@Param("name") String name);
 
+		// DATAJDBC-182
 		@Modifying
 		@Query("INSERT INTO DUMMYENTITY (name) VALUES(:name)")
 		void insert(@Param("name") String name);