我正在尝试使用 Datastax 4.2.2 编写 DAO 接口，但遇到了几个编译错误

Question

我有以下 POJO：

@Table(name = "order", readConsistency = "QUORUM", writeConsistency = "QUORUM")
public class Order {    
    
    @Column(name = "id")
    @PartitionKey
    private String id;

    @Column(name = "customer_id")
    private String customerId;

    @Column(name = "loyalty_id")
    private String loyaltyId;

    @Column(name = "customer_email")
    private String customerEmail;

    public Order() {

    }
    ... getters and setters
}

现在我正在编写 OrderDao 如下：

    import com.datastax.oss.driver.api.mapper.annotations.*;

    @Dao
    public interface OrderDao {
            @Select
            Order findById(String orderId);

            @Insert
            void save(Order order);

            @Delete
            void delete(Order order);
    }

当我这样做时 ./gradlew build 我得到以下错误：

error: Invalid return type: Select methods must return one of [ENTITY, OPTIONAL_ENTITY, FUTURE_OF_ENTITY, FUTURE_OF_OPTIONAL_ENTITY, PAGING_ITERABLE, FUTURE_OF_ASYNC_PAGING_ITERABLE]
    Order findById(String orderId);

error: Insert methods must take the entity to insert as the first parameter
    void save(Order order);
         ^

error: Missing entity class: Delete methods that do not operate on an entity instance must have an 'entityClass' argument
    void delete(Order order);
         ^

我正在按照此处的文档进行实施：https://docs.datastax.com/en/developer/java-driver/4.2/manual/mapper/。这可能是什么原因？

谢谢。

Answer 1

您在 Order class 上缺少 @Entity 注释：

@Entity
@Table(name = "order", readConsistency = "QUORUM", writeConsistency = "QUORUM")
public class Order {

我正在尝试使用 Datastax 4.2.2 编写 DAO 接口，但遇到了几个编译错误

I am trying to write a DAO interface using Datastax 4.2.2, but getting several compile errors

java

gradle

datastax-java-driver

datastax