DATAJDBC-175 - Supports simple types as return type for annotated methods.

Original pull request: #43.

src/main/java/org/springframework/data/jdbc/mapping/model/JdbcMappingContext.java

@@ -44,6 +44,7 @@ import org.springframework.jdbc.core.namedparam.NamedParameterJdbcOperations;
  *
  * @author Jens Schauder
  * @author Greg Turnquist
+ * @author Kazuki Shimizu
  * @since 2.0
  */
 public class JdbcMappingContext extends AbstractMappingContext<JdbcPersistentEntity<?>, JdbcPersistentProperty> {
@@ -56,6 +57,7 @@ public class JdbcMappingContext extends AbstractMappingContext<JdbcPersistentEnt
 
 	@Getter private final NamingStrategy namingStrategy;
 	@Getter private final NamedParameterJdbcOperations template;
+	@Getter private SimpleTypeHolder simpleTypeHolder;
 	private GenericConversionService conversions = getDefaultConversionService();
 
 	public JdbcMappingContext(NamingStrategy namingStrategy, NamedParameterJdbcOperations template,
@@ -72,6 +74,12 @@ public class JdbcMappingContext extends AbstractMappingContext<JdbcPersistentEnt
 		this(new DefaultNamingStrategy(), template, __ -> {});
 	}
 
+	@Override
+	public void setSimpleTypeHolder(SimpleTypeHolder simpleTypes) {
+		super.setSimpleTypeHolder(simpleTypes);
+		this.simpleTypeHolder = simpleTypes;
+	}
+
 	public List<PropertyPath> referencedEntities(Class<?> rootType, PropertyPath path) {
 
 		List<PropertyPath> paths = new ArrayList<>();

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

@@ -17,6 +17,7 @@ package org.springframework.data.jdbc.repository.support;
 
 import java.lang.reflect.Method;
 
+import org.springframework.core.convert.ConversionService;
 import org.springframework.data.jdbc.core.DataAccessStrategy;
 import org.springframework.data.jdbc.core.EntityRowMapper;
 import org.springframework.data.jdbc.mapping.model.JdbcMappingContext;
@@ -27,22 +28,26 @@ import org.springframework.data.repository.query.EvaluationContextProvider;
 import org.springframework.data.repository.query.QueryLookupStrategy;
 import org.springframework.data.repository.query.RepositoryQuery;
 import org.springframework.jdbc.core.RowMapper;
+import org.springframework.jdbc.core.SingleColumnRowMapper;
 
 /**
  * {@link QueryLookupStrategy} for JDBC repositories. Currently only supports annotated queries.
  *
  * @author Jens Schauder
+ * @author Kazuki Shimizu
  */
 class JdbcQueryLookupStrategy implements QueryLookupStrategy {
 
 	private final JdbcMappingContext context;
 	private final DataAccessStrategy accessStrategy;
+	private final ConversionService conversionService;
 
 	JdbcQueryLookupStrategy(EvaluationContextProvider evaluationContextProvider, JdbcMappingContext context,
 			DataAccessStrategy accessStrategy) {
 
 		this.context = context;
 		this.accessStrategy = accessStrategy;
+		this.conversionService = context.getConversions();
 	}
 
 	@Override
@@ -50,10 +55,12 @@ class JdbcQueryLookupStrategy implements QueryLookupStrategy {
 			ProjectionFactory projectionFactory, NamedQueries namedQueries) {
 
 		JdbcQueryMethod queryMethod = new JdbcQueryMethod(method, repositoryMetadata, projectionFactory);
-		Class<?> domainType = queryMethod.getReturnedObjectType();
-		RowMapper<?> rowMapper = new EntityRowMapper<>(context.getRequiredPersistentEntity(domainType),
-				context.getConversions(), context, accessStrategy);
-
+		Class<?> returnedObjectType = queryMethod.getReturnedObjectType();
+		RowMapper<?> rowMapper = context.getSimpleTypeHolder().isSimpleType(returnedObjectType)
+				? SingleColumnRowMapper.newInstance(returnedObjectType, conversionService)
+				: new EntityRowMapper<>(context.getRequiredPersistentEntity(returnedObjectType), conversionService,
+						context, accessStrategy);
 		return new JdbcRepositoryQuery(queryMethod, context, rowMapper);
 	}
+
 }

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

@@ -33,6 +33,8 @@ 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;
@@ -165,6 +167,48 @@ public class QueryAnnotationHsqlIntegrationTests {
 				.containsExactlyInAnyOrder("a", "b");
 
 	}
+	
+	@Test // DATAJDBC-175
+	public void executeCustomQueryWithReturnTypeIsNubmer() {
+
+		repository.save(dummyEntity("aaa"));
+		repository.save(dummyEntity("bbb"));
+		repository.save(dummyEntity("cac"));
+
+		int count = repository.countByNameContaining("a");
+
+		assertThat(count).isEqualTo(2);
+
+	}
+
+	@Test // DATAJDBC-175
+	public void executeCustomQueryWithReturnTypeIsBoolean() {
+
+		repository.save(dummyEntity("aaa"));
+		repository.save(dummyEntity("bbb"));
+		repository.save(dummyEntity("cac"));
+
+		assertThat(repository.existsByNameContaining("a")).isTrue();
+		assertThat(repository.existsByNameContaining("d")).isFalse();
+
+	}
+
+	@Test // DATAJDBC-175
+	public void executeCustomQueryWithReturnTypeIsDate() {
+
+		Date now = new Date();
+		assertThat(repository.nowWithDate()).isAfterOrEqualsTo(now);
+
+	}
+
+	@Test // DATAJDBC-175
+	public void executeCustomQueryWithReturnTypeIsLocalDateTimeList() {
+
+		LocalDateTime now = LocalDateTime.now();
+		repository.nowWithLocalDateTimeList() //
+				.forEach(d -> assertThat(d).isAfterOrEqualTo(now));
+
+	}
 
 	private DummyEntity dummyEntity(String name) {
 
@@ -209,5 +253,17 @@ public class QueryAnnotationHsqlIntegrationTests {
 		@Query("SELECT * FROM DUMMYENTITY")
 		Stream<DummyEntity> findAllWithReturnTypeIsStream();
 
+		@Query("SELECT count(*) FROM DUMMYENTITY WHERE name like '%' || :name || '%'")
+		int countByNameContaining(@Param("name") String name);
+
+		@Query("SELECT count(*) FROM DUMMYENTITY WHERE name like '%' || :name || '%'")
+		boolean existsByNameContaining(@Param("name") String name);
+
+		@Query("VALUES (current_timestamp)")
+		Date nowWithDate();
+
+		@Query("VALUES (current_timestamp),(current_timestamp)")
+		List<LocalDateTime> nowWithLocalDateTimeList();
+
 	}
 }