java - 缺少具有 EmbeddedId 的实体的默认构造函数

Question

当我尝试从 JPA 存储库获取实体列表时，总是会遇到这样的异常

org.springframework.orm.jpa.JpaSystemException: No default constructor for entity:  : pl.hycom.hyper.hyebok.model.ServiceEntity$Id; nested exception is org.hibernate.InstantiationException: No default constructor for entity:  : pl.hycom.hyper.hyebok.model.ServiceEntity$Id

我的实体中缺少什么。我在 Embeddable 类和外部类中都有非参数构造函数和全参数构造函数。我找不到这个问题的解决方案。

下面是我的实体

@Entity
@Table(name = "he_service")
public class ServiceEntity implements Serializable {

    @EmbeddedId
    private Id id ;
    private String name;

    public ServiceEntity() {
    }

    public ServiceEntity(Id id, String name) {
        this.id = id;
        this.name = name;
    }

    @Embeddable
    class Id implements Serializable {

        public Id() {
        }

        public Id(String serviceId, String clientId) {
            this.serviceId = serviceId;
            this.clientId = clientId;
        }

        @Column(name = "serviceId")
        private String serviceId;
        @Column(name = "clientId")
        private String clientId;

        public String getServiceId() {
            return serviceId;
        }

        public void setServiceId(String serviceId) {
            this.serviceId = serviceId;
        }

        public String getClientId() {
            return clientId;
        }

        public void setClientId(String clientId) {
            this.clientId = clientId;
        }


   }

存储库方法有

   @Query(value= "SELECT s FROM ServiceEntity s " +
            "WHERE s.id.clientId = :clientId")
    List<ServiceEntity> findByClientId(@Param("clientId") String clientId);

Answer 1

您的内部 Id 类是非静态的，这意味着它创建一个构造函数

class Id implements Serializable {

    public Id(ServiceEntity arg0) {
    }
    // …
}

将其更改为静态类

static class Id implements Serializable {
    // …
}