java - Spring Data JPA( hibernate )nullpointer添加实体列表时发生异常

首先是我的代码。

专业化

@Entity
public class Specialization {

    @Id
    private String name;

    @OneToMany(cascade = CascadeType.ALL)
    @JoinColumn(name="att_id", referencedColumnName="ID")
    private List<Attribute> attributes;

    //Getters and Setters
}

属性

@Entity
public class Attribute {

    @Id
    @GeneratedValue(strategy= GenerationType.AUTO)
    private Long id;

    private String name;
    private double scaling;

    //Getters and Setters
}

我的问题是我得到以下异常:

Caused by: java.lang.NullPointerException
    at org.hibernate.cfg.annotations.CollectionBinder.bindCollectionSecondPass(CollectionBinder.java:1460)
    at org.hibernate.cfg.annotations.CollectionBinder.bindOneToManySecondPass(CollectionBinder.java:864)
    at org.hibernate.cfg.annotations.CollectionBinder.bindStarToManySecondPass(CollectionBinder.java:779)
    at org.hibernate.cfg.annotations.CollectionBinder$1.secondPass(CollectionBinder.java:728)
    at org.hibernate.cfg.CollectionSecondPass.doSecondPass(CollectionSecondPass.java:70)
    at org.hibernate.cfg.Configuration.originalSecondPassCompile(Configuration.java:1697)
    at org.hibernate.cfg.Configuration.secondPassCompile(Configuration.java:1426)
    at org.hibernate.cfg.Configuration.buildSessionFactory(Configuration.java:1846)
    at org.hibernate.jpa.boot.internal.EntityManagerFactoryBuilderImpl$4.perform(EntityManagerFactoryBuilderImpl.java:852)
    at org.hibernate.jpa.boot.internal.EntityManagerFactoryBuilderImpl$4.perform(EntityManagerFactoryBuilderImpl.java:845)
    at org.hibernate.boot.registry.classloading.internal.ClassLoaderServiceImpl.withTccl(ClassLoaderServiceImpl.java:398)
    at org.hibernate.jpa.boot.internal.EntityManagerFactoryBuilderImpl.build(EntityManagerFactoryBuilderImpl.java:844)
    at org.springframework.orm.jpa.vendor.SpringHibernateJpaPersistenceProvider.createContainerEntityManagerFactory(SpringHibernateJpaPersistenceProvider.java:60)
    at org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean.createNativeEntityManagerFactory(LocalContainerEntityManagerFactoryBean.java:343)
    at org.springframework.orm.jpa.AbstractEntityManagerFactoryBean.afterPropertiesSet(AbstractEntityManagerFactoryBean.java:318)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.invokeInitMethods(AbstractAutowireCapableBeanFactory.java:1625)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1562)
    ... 98 more

仅在将属性attributes添加到Class Specialization后才发生此异常。因此，没有此属性，一切正常，但如果添加此属性，则会出现异常。我不明白我在做什么。
也许有人可以发现我的错误？

附加信息:

Hibernate Core版本:4.3.7。最后。

还有另一个与Specificationization具有oneToMany关系的Entity GameClass =>每个GameClass具有多个Specialization，每个Specialization具有多个Attribute。

不知道这是否重要，但这是一个Spring-Boot应用程序

最佳答案

我有我的错。睡觉有点帮助。
我把关系弄混了。

如果一个Specialization具有许多Attribute，则注释应如下所示:

@OneToMany(cascade = CascadeType.ALL)
@JoinColumn(name="specc_id", referencedColumnName = "name")
private List<Attribute> attributes;

和 NOT 像这样:

@OneToMany(cascade = CascadeType.ALL)
@JoinColumn(name="att_id", referencedColumnName="ID")
private List<Attribute> attributes;