英文:
I am trying to write a DAO interface using Datastax 4.2.2, but getting several compile errors
问题
以下是翻译好的内容：
我有以下的POJO：
@Table(name = "order", readConsistency = "QUORUM", writeConsistency = "QUORUM")public class Order {@Column(name = "id")@PartitionKeyprivate 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() {}... 获取器和设置器}
现在我正在编写如下的OrderDao：
import com.datastax.oss.driver.api.mapper.annotations.*;@Daopublic interface OrderDao {@SelectOrder findById(String orderId);@Insertvoid save(Order order);@Deletevoid delete(Order order);}
当我执行 ./gradlew build 时，我得到以下错误：
error: 无效的返回类型：Select 方法必须返回 [ENTITY、OPTIONAL_ENTITY、FUTURE_OF_ENTITY、FUTURE_OF_OPTIONAL_ENTITY、PAGING_ITERABLE、FUTURE_OF_ASYNC_PAGING_ITERABLE] 中的一个Order findById(String orderId);
error: Insert 方法必须将要插入的实体作为第一个参数void save(Order order);^
error: 缺少实体类：不操作实体实例的 Delete 方法必须有一个 'entityClass' 参数void delete(Order order);^
我正在按照这里的文档进行实现：https://docs.datastax.com/en/developer/java-driver/4.2/manual/mapper/ 。可能的原因是什么？
谢谢。
英文:
I have the following POJO:
@Table(name = "order", readConsistency = "QUORUM", writeConsistency = "QUORUM")public class Order {@Column(name = "id")@PartitionKeyprivate 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}
And now I am writing the OrderDao as following:
import com.datastax.oss.driver.api.mapper.annotations.*;@Daopublic interface OrderDao {@SelectOrder findById(String orderId);@Insertvoid save(Order order);@Deletevoid delete(Order order);}
And when I do ./gradlew build I get the following errors:
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 parametervoid save(Order order);^
error: Missing entity class: Delete methods that do not operate on an entity instance must have an 'entityClass' argumentvoid delete(Order order);^
I am implementing by following the documentation here: https://docs.datastax.com/en/developer/java-driver/4.2/manual/mapper/ . What could be the possible cause of this?
Thanks.
答案1
得分: 2
你的Order类缺少@Entity注解：
@Entity@Table(name = "order", readConsistency = "QUORUM", writeConsistency = "QUORUM")public class Order {
英文:
You are missing the @Entity annotation on your Order class:
@Entity@Table(name = "order", readConsistency = "QUORUM", writeConsistency = "QUORUM")public class Order {
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