Given the following entity…

@Entity
@Getter
@Setter
public class OrderDTD {

    private Long id;
    ...
    
    private String orderType;
    private String orderStatus;
    

… and the following view…

public interface OrderStatsView {

  /** Gets the order type. */
  String getOrderType();

  /** Gets the total number of orders. */
  Long getOrderCount();

  /** Gets the number of executed orders. */
  Long getExecutedOrderCount();
}

… I’ve created a method to retrieve some stats for a given order:

@Repository
public interface OrderRepository
    extends JpaRepository<OrderDTD, Long> {

    ...

    @Query("SELECT o.orderType AS orderType,"
        + " COUNT(o.orderStatus) AS orderCount,"
        + " COUNT(CASE WHEN o.orderStatus = 'EXECUTED'"
        + " THEN 1 END) AS executedOrderCount"
        + " FROM OrderDTD o"
        + " WHERE o.orderType = :orderType"
        + " GROUP BY o.orderType")
    @Cacheable("orderStatsView")
    Optional<OrderStatsView> getOrderStats(@NonNull String orderType);

    @Override
    @CacheEvict(value = "orderStatsView", key = "#p0.orderType")
    <T extends OrderDTD> T save(T order);
}

Method getOrderStats() works as expected without caching… whereas when I enable caching with @Cacheable, I always get this error:

com.hazelcast.nio.serialization.HazelcastSerializationException: Failed to serialize 'jdk.proxy3.$Proxy584'

Am I missing something? Any help would be really appreciated 🙂