DATAJPA-506 - Add support for conversion of Blob values to byte[] in native queries.

JpaQueryExecution no applies type conversion for Blob instances to be able to return byte[] from repository calls.

Original pull request: #72.

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

@@ -1390,6 +1390,23 @@ public class UserRepositoryTests {
 		flushTestUsers();
 
 		byte[] result = null; // repository.findBinaryDataByIdJpaQl(firstUser.getId());
+
+		assertThat(result.length, is(data.length));
+		assertThat(result, is(data));
+	}
+
+	/**
+	 * @see DATAJPA-506
+	 */
+	@Test
+	public void findBinaryDataByIdNative() throws Exception {
+
+		byte[] data = "Woho!!".getBytes("UTF-8");
+		firstUser.setBinaryData(data);
+
+		flushTestUsers();
+
+		byte[] result = repository.findBinaryDataByIdNative(firstUser.getId());
 		assertThat(result.length, is(data.length));
 		assertThat(result, is(data));
 	}

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

@@ -445,4 +445,10 @@ public interface UserRepository extends JpaRepository<User, Integer>, JpaSpecifi
 	 * @see DATAJPA-551
 	 */
 	Slice<User> findTop2UsersBy(Pageable page);
+	
+	/**
+	 * @see DATAJPA-506
+	 */
+	@Query(value = "select u.binaryData from User u where u.id = ?", nativeQuery = true)
+	byte[] findBinaryDataByIdNative(Integer id);
 }