Question

任何人都可以解释我为什么在进行合并时得到TransientObjectException。只有当我在ActivityTestEntity的构造函数中创建RuleTestEntitiy时才会重现问题，如下所示。如果我更新或创建，它不会出现。

提前致谢。

这是一个测试：



@ContextConfiguration(locations = {
    "classpath:testApplicationContext_db.xml"})
public class TransientObjectExceptionTest extends  AbstractTestNGSpringContextTests{
@Autowired
SessionFactory sessionFactory;
@Test
public void testAddTestActivity(){
    Session session = sessionFactory.openSession();
    Transaction tx1 = session.beginTransaction();
    ActivityTestEntity newActivityEntity = new ActivityTestEntity();
    session.merge(newActivityEntity);
    tx1.commit();
    session.close();
    sessionFactory.close();
}


}

@ContextConfiguration(locations = { "classpath:testApplicationContext_db.xml"}) public class TransientObjectExceptionTest extends AbstractTestNGSpringContextTests{ @Autowired SessionFactory sessionFactory; @Test public void testAddTestActivity(){ Session session = sessionFactory.openSession(); Transaction tx1 = session.beginTransaction(); ActivityTestEntity newActivityEntity = new ActivityTestEntity(); session.merge(newActivityEntity); tx1.commit(); session.close(); sessionFactory.close(); } 例外： org.hibernate.TransientObjectException：object引用未保存的瞬态实例 - 在刷新之前保存瞬态实例：com.xxx.RuleTestEntity

@Entity
@Table(name = "ACTIVITY_TEST")
public class ActivityTestEntity implements Serializable{
private static final long serialVersionUID = 4190826330152288861L;
@Id
@GeneratedValue(strategy = GenerationType.AUTO)
@Column(name = "ACTIVITY_ID", nullable = false)
private long id;
@OneToMany(mappedBy = "activity", cascade = CascadeType.ALL, fetch = FetchType.EAGER, orphanRemoval = true)
private Set<RuleTestEntity> rules = new HashSet<>();
public ActivityTestEntity() {
    RuleTestEntity rule = new RuleTestEntity();
    rule.setActivity(this);
    this.getRules().add(rule);
}
public long getId() {
    return id;
}
public void setId(long id) {
    this.id = id;
}
public Set<RuleTestEntity> getRules() {
    return rules;
}
public void setRules(Set<RuleTestEntity> rules) {
    this.rules = rules;
}

@Entity
@Table(name = "ACTIVITY_TEST")
public class ActivityTestEntity implements Serializable{
private static final long serialVersionUID = 4190826330152288861L;
@Id
@GeneratedValue(strategy = GenerationType.AUTO)
@Column(name = "ACTIVITY_ID", nullable = false)
private long id;
@OneToMany(mappedBy = "activity", cascade = CascadeType.ALL, fetch = FetchType.EAGER, orphanRemoval = true)
private Set<RuleTestEntity> rules = new HashSet<>();
public ActivityTestEntity() {
    RuleTestEntity rule = new RuleTestEntity();
    rule.setActivity(this);
    this.getRules().add(rule);
}
public long getId() {
    return id;
}
public void setId(long id) {
    this.id = id;
}
public Set<RuleTestEntity> getRules() {
    return rules;
}
public void setRules(Set<RuleTestEntity> rules) {
    this.rules = rules;
}

Answer 1

当您尝试保存引用未保存实体的实体时，会生成此异常。您可以先保存引用的实体，然后保存实体，也可以将cascade=CascadeType.All添加到它们之间的关系中。

删除构造函数中的代码，然后尝试以下代码：

    Session session = sessionFactory.openSession();
    Transaction tx1 = session.beginTransaction();
    RuleTestEntity rule = new RuleTestEntity();
    session.save(rule);
    session.refresh(rule);
    ActivityTestEntity newActivityEntity = new ActivityTestEntity();
    Set<RuleTestEntity> rules = new HashSet<>();
    rules.add(rule);
    session.merge(newActivityEntity);
    tx1.commit();
    session.close();
    sessionFactory.close();

TransientObjectException：对象引用未保存的瞬态实例 - 在进行合并时，在刷新之前保存瞬态实例

1 个答案: