如何使用休眠映射泛型集合

Question

我有一个带有泛型列表的包装类

    @Entity
     public class Rubrique<T> {
...
    @OneToMany(cascade = CascadeType.ALL, mappedBy = "declaration", fetch = FetchType.LAZY, orphanRemoval = true)
    List<T> items = new ArrayList<T>();
...

我是这样使用它的：

@Entity
public class Declar {
    Rubrique<ActivConsultant> activConsultant = new Rubrique<ActivConsultant>();
    public Rubrique<ActivConsultant> getActivConsultant() {
        return activConsultant;
    }

在这里，我的班级活动顾问：

@Entity
public class ActivConsultant  {
    @ManyToOne
    private Rubrique<?> rubrique;
...

但是我无法将这些实体与休眠映射，我有此错误：

org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'entityManagerFactory' defined in class path resource [org/springframework/boot/autoconfigure/orm/jpa/HibernateJpaConfiguration.class]: Invocation of init method failed; nested exception is org.hibernate.AnnotationException: Property fr.hatvp.parsatorApp.model.Rubrique.items has an unbound type and no explicit target entity. Resolve this Generic usage issue or set an explicit target attribute (eg @OneToMany(target=) or use an explicit @Type
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1778) ~[spring-beans-5.1.7.RELEASE.jar:5.1.7.RELEASE]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:593) ~[spring-beans-5.1.7.RELEASE.jar:5.1.7.RELEASE]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:515) ~[spring-beans-5.1.7.RELEASE.jar:5.1.7.RELEASE]
    at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:320) ~[spring-beans-5.1.7.RELEASE.jar:5.1.7.RELEASE]
    at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:222) ~[spring-beans-5.1.7.RELEASE.jar:5.1.7.RELEASE]
    at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:318) ~[spring-beans-5.1.7.RELEASE.jar:5.1.7.RELEASE]
    at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:199) ~[spring-beans-5.1.7.RELEASE.jar:5.1.7.RELEASE]
    at org.springframework.context.support.AbstractApplicationContext.getBean(AbstractApplicationContext.java:1105) ~[spring-context-5.1.7.RELEASE.jar:5.1.7.RELEASE]
    at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:867) ~[spring-context-5.1.7.RELEASE.jar:5.1.7.RELEASE]
    at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:549) ~[spring-context-5.1.7.RELEASE.jar:5.1.7.RELEASE]
    at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:775) [spring-boot-2.1.5.RELEASE.jar:2.1.5.RELEASE]
    at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:397) [spring-boot-2.1.5.RELEASE.jar:2.1.5.RELEASE]
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:316) [spring-boot-2.1.5.RELEASE.jar:2.1.5.RELEASE]
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:1260) [spring-boot-2.1.5.RELEASE.jar:2.1.5.RELEASE]
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:1248) [spring-boot-2.1.5.RELEASE.jar:2.1.5.RELEASE]
    at fr.hatvp.parsatorApp.ParsatorApplication.main(ParsatorApplication.java:17) [classes/:na]
Caused by: org.hibernate.AnnotationException: Property fr.hatvp.parsatorApp.model.Rubrique.items has an unbound type and no explicit target entity. Resolve this Generic usage issue or set an explicit target attribute (eg @OneToMany(target=) or use an explicit @Type

Answer 1

不能将泛型与 Hibernate 一起使用 Hibernate 如何知道列表项应该映射哪个数据库表？

这也正是错误消息所说的：

属性 fr.hatvp.parsatorApp.model.Rubrique.items 具有未绑定类型 并且没有明确的目标实体。解决此通用使用问题或集 显式目标属性(例如 @OneToMany(target=( 或使用 显式@Type