DATAJPA-505 - Projections for basic primitive arrays should use SingleEntityExecution.

We now execute a query as a SingleEntityExecution if the return-type of the particular query-method is an basic char[],Character[], byte[], Byte[].
Previously we tried to do an CollectionExecution which didn't return all elements of the actual result (e.g. the byte[]).

Although EclipseLink and Hibernate support the use of array elements in projections OpenJPA seems not to. Filed https://issues.apache.org/jira/browse/OPENJPA-2484 to track the issue. Since OpenJPA prevents the bootstrap of the whole test suite I had to comment the query method + tests out. Tested Hibernate / EclipseLink by temporarily excluding all OpenJPA tests from the test-suite.

Original pull request: #71.

src/main/java/org/springframework/data/jpa/repository/query/JpaQueryMethod.java

@@ -20,7 +20,10 @@ import static org.springframework.core.annotation.AnnotationUtils.*;
 import java.lang.reflect.Method;
 import java.util.ArrayList;
 import java.util.Arrays;
+import java.util.Collections;
+import java.util.HashSet;
 import java.util.List;
+import java.util.Set;
 
 import javax.persistence.LockModeType;
 import javax.persistence.QueryHint;
@@ -47,6 +50,20 @@ import org.springframework.util.StringUtils;
  */
 public class JpaQueryMethod extends QueryMethod {
 
+	// @see JPA 2.0 Specification 2.2 Persistent Fields and Properties Page 23 - Top paragraph.
+	private static final Set<Class<?>> NATIVE_ARRAY_TYPES;
+
+	static {
+
+		Set<Class<?>> types = new HashSet<Class<?>>(4);
+		types.add(byte[].class);
+		types.add(Byte[].class);
+		types.add(char[].class);
+		types.add(Character[].class);
+
+		NATIVE_ARRAY_TYPES = Collections.unmodifiableSet(types);
+	}
+
 	private final QueryExtractor extractor;
 	private final Method method;
 
@@ -275,4 +292,13 @@ public class JpaQueryMethod extends QueryMethod {
 	public JpaParameters getParameters() {
 		return (JpaParameters) super.getParameters();
 	}
+
+	/* 
+	 * (non-Javadoc)
+	 * @see org.springframework.data.repository.query.QueryMethod#isCollectionQuery()
+	 */
+	@Override
+	public boolean isCollectionQuery() {
+		return super.isCollectionQuery() && !NATIVE_ARRAY_TYPES.contains(method.getReturnType());
+	}
 }

src/test/java/org/springframework/data/jpa/repository/UserRepositoryTests.java

@@ -1214,6 +1214,7 @@ public class UserRepositoryTests {
 		List<User> result = repository.findByBinaryData(data);
 		assertThat(result, hasSize(1));
 		assertThat(result, hasItem(firstUser));
+		assertThat(result.get(0).getBinaryData(), is(data));
 	}
 
 	/**
@@ -1279,6 +1280,24 @@ public class UserRepositoryTests {
 		assertThat(result, hasSize(2));
 		assertThat(result, hasItems(firstUser, secondUser));
 	}
+	
+	/**
+	 * @see DATAJPA-505
+	 * @see https://issues.apache.org/jira/browse/OPENJPA-2484
+	 */
+	@Test
+	@Ignore
+	public void findBinaryDataByIdJpaQl() throws Exception {
+
+		byte[] data = "Woho!!".getBytes("UTF-8");
+		firstUser.setBinaryData(data);
+
+		flushTestUsers();
+
+		byte[] result = null; // repository.findBinaryDataByIdJpaQl(firstUser.getId());
+		assertThat(result.length, is(data.length));
+		assertThat(result, is(data));
+	}
 
 	private Page<User> executeSpecWithSort(Sort sort) {
 

src/test/java/org/springframework/data/jpa/repository/sample/UserRepository.java

@@ -311,4 +311,11 @@ public interface UserRepository extends JpaRepository<User, Integer>, JpaSpecifi
 	 * @see DATAJPA-496
 	 */
 	List<User> findByAttributesIn(Set<String> attributes);
+	
+	/**
+	 * @see DATAJPA-505
+	 * @see https://issues.apache.org/jira/browse/OPENJPA-2484
+	 */
+	// @Query(value = "select u.binaryData from User u where u.id = :id")
+	// byte[] findBinaryDataByIdJpaQl(@Param("id") Integer id);
 }