inheritance - Kotlin域类转换为子类

Question

我有一个域名类(class)

@Entity
@Table(name = "user")
open class User(
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    open var id: Long = 0L,

    @Column(nullable = false)
    var name: String? = null)

我有一个该域类的子类，我想添加一个JsonIgnore批注:

open class UserFiltered(
    @Id
    @JsonIgnore
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    override var id: Long = 0L
): User()

但是，当我尝试将用户转换为UserFiltered时:

return ResponseModel<UserFiltered>(true, userModified as UserFiltered)

我收到以下错误:

java.lang.ClassCastException: com.example.platform.database.domain.User cannot be cast to com.example.platform.model.UserFiltered at com.example.platform.controller.UserController.modifyUser(UserController.kt:71) ~[classes/:na]

有没有一种方法可以在Kotlin中实现这一目标，或者我将必须进行完整的转换，在User上设置每个参数？

Answer 1

我不得不将子类修改为以下形式:

open class UserFiltered(
    @Id
    @JsonIgnore
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    override var id: Long = 0L
): User(){
    constructor(user: User): this(user.id)
}

并创建UserFiltered的实例

return ResponseModel<UserFiltered>(true, UserFiltered(userModified))