Question

我有以下实体在hibernate插入期间工作正常。

User.java

@Entity
@Table
@Inheritance(strategy = InheritanceType.JOINED)
public class User extends PersistentObject {

    private static final long serialVersionUID = -1803375723276957167L;

    // commenting this association allows update to work successfully.
    @OneToOne(fetch = FetchType.LAZY, mappedBy = "user", cascade = CascadeType.ALL, orphanRemoval = true)
    private ContactInfo contactInfo;
    private String name;
}

然后，我尝试对我认为已分离的实体执行更新，并在cascadeOnUpdate期间获取空指针异常。

异常

java.lang.NullPointerException
    at org.hibernate.engine.spi.EntityEntry.getLoadedValue(EntityEntry.java:274)
    at org.hibernate.engine.internal.Cascade.cascadeProperty(Cascade.java:236)
    at org.hibernate.engine.internal.Cascade.cascade(Cascade.java:165)
    at org.hibernate.engine.internal.Cascade.cascade(Cascade.java:132)
    at org.hibernate.event.internal.DefaultSaveOrUpdateEventListener.cascadeOnUpdate(DefaultSaveOrUpdateEventListener.java:361)
    at org.hibernate.event.internal.DefaultSaveOrUpdateEventListener.performUpdate(DefaultSaveOrUpdateEventListener.java:335)
    at org.hibernate.event.internal.DefaultSaveOrUpdateEventListener.entityIsDetached(DefaultSaveOrUpdateEventListener.java:239)
    at org.hibernate.event.internal.DefaultSaveOrUpdateEventListener.performSaveOrUpdate(DefaultSaveOrUpdateEventListener.java:109)
    at org.hibernate.event.internal.DefaultSaveOrUpdateEventListener.onSaveOrUpdate(DefaultSaveOrUpdateEventListener.java:90)
    at org.hibernate.internal.SessionImpl.fireSaveOrUpdate(SessionImpl.java:724)
    at org.hibernate.internal.SessionImpl.saveOrUpdate(SessionImpl.java:716)
    at org.hibernate.internal.SessionImpl.saveOrUpdate(SessionImpl.java:712)
    at com.myapp.dao.GenericHibernateDAO.save(GenericHibernateDAO.java:279)
    at com.myapp.service.StaffInfoServiceImpl.storeInfo(StaffInfoServiceImpl.java:74)
    at com.myapp.service.StaffInfoServiceImpl.storeInfo(StaffInfoServiceImpl.java:1)

更新

ContactInfo.java

@Entity
@Table
@DynamicUpdate
public class ContactInfo implements Serializable {

    private static final long serialVersionUID = 4485388013971134422L;

    @Column
    @Length(min = 3, max = 50)
    private String currentCity;

    @ManyToOne
    @JoinColumn(name = "current_country_id")
    private Country currentCountry;

    @Column(columnDefinition = "char(10)")
    private String currentPostCode;

    @Column
    @Length(min = 3, max = 50)
    private String currentState;

    @Column
    @Length(min = 3, max = 50)
    private String currentStreetOne;

    @Column
    @Length(min = 3, max = 50)
    private String currentStreetThree;

    @Column
    @Length(min = 3, max = 50)
    private String currentStreetTwo;

    @Column
    @Email
    private String email;

    @Column
    @Length(max = 20)
    private String fax;

    @Column
    @Length(max = 20)
    private String homePhone;

    @GenericGenerator(name = "generator", strategy = "foreign", parameters = @Parameter(name = "property", value = "user"))
    @Id
    @GeneratedValue(generator = "generator")
    @Column(name = "user_id", unique = true, nullable = false)
    private Long id;

    @Column
    @Length(max = 20)
    private String mobilePhone;

    @Column
    @Length(max = 20)
    private String officePhone;

    @Column
    @Length(min = 3, max = 50)
    private String permanentCity;

    @ManyToOne
    @JoinColumn(name = "permanent_country_id")
    private Country permanentCountry;

    @Column(columnDefinition = "char(10)")
    private String permanentPostCode;

    @Column
    @Length(min = 3, max = 50)
    private String permanentState;

    @Column
    @Length(min = 3, max = 50)
    private String permanentStreetOne;

    @Column
    @Length(min = 3, max = 50)
    private String permanentStreetThree;

    @Column
    @Length(min = 3, max = 50)
    private String permanentStreetTwo;

    @OneToOne(fetch = FetchType.LAZY)
    @PrimaryKeyJoinColumn
    private User user;

    @Version
    @Column(name = "version")
    private Integer version = 0;   
}

我的问题是为什么在插入期间不会在更新期间抛出异常呢？我在这里想念的是什么？

Answer 1

我认为此错误是由于orphanRemoval = true关联中的@OneToOne属性造成的。

当您使用User null引用更新ContactInfo时，hibernate可能会假设ContactInfo引用设置为null然后它尝试删除'在那里（但从未存在）'的对象，因为orphanRemoval语义。

如果我对这个错误的逻辑是真的，那么hibernate中就有一个错误。也许这是在较新版本的hibernate中修复的。

Answer 2

这是hibernate的bug，已在版本4.1.7中修复您的版本的临时解决方法是使用session.merge而不是session.saveOrUpdate。

问题已在此task

下修复

Hibernate级联更新提供空指针

2 个答案: