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

Question

在项目中,我有User,Role,UserRole和BloodGroup实体.首先,我List<BloodGroup>从数据库中取出并设置为User.然后我给予User并Role参与其中UserRole.之后我插入User到DB,然后我尝试插入UserRole,但是我收到一个错误.当我查看DB时,ID BloodGroup未插入User表中.

如果我选择BloodGroup列表中的第一个,我会收到错误.其他选择是正常的.

我发现cascade = CascadeType.ALL,我看着互联网,但这会添加相同的数据BloodGroup,这意味着我有更多的Arh + BloodGroup.

实体:

@Entity
@Table(name="USERS")
public class User implements Serializable {

    private static final long serialVersionUID = 1L;

    @Id
    @GeneratedValue(strategy=GenerationType.AUTO)
    private long userid;

    @OneToMany(mappedBy="user")
    private List<Userrole> userroles;

    //bi-directional many-to-one association to Bloodgroup
    @ManyToOne
    @JoinColumn(name="BLOODGRUPID")
    private Bloodgroup bloodgroup;

}

---

@Entity
public class Bloodgroup implements Serializable {

    private static final long serialVersionUID = 1L;

    @Id
    @GeneratedValue(strategy=GenerationType.AUTO)
    private int bloodgroupid;

    private String bloodgroupname;

    @OneToMany(mappedBy="bloodgroup")
    private List<User> users;

}

---

@Entity
public class Userrole implements Serializable {

    private static final long serialVersionUID = 1L;

    @Id
    @GeneratedValue(strategy=GenerationType.AUTO)
    private long userroleid;

    private Timestamp createddate;

    private Timestamp deleteddate;

    private String isactive;

    //bi-directional many-to-one association to Role
    @ManyToOne
    @JoinColumn(name="ROLEID")
    private Role role;

    //bi-directional many-to-one association to User
    @ManyToOne
    @JoinColumn(name="USERID")
    private User user;

}

控制器:

user.setBloodgroup(bloodGroupImpl.getBloodGroupById(bGroup));
user.setUserid(userImpl.insertUserProfile(user));
userRoleImpl.insertUserRole(user,role);

DAO:

public void insertUserRole(User user, Role role) {
    Session session =getHibernateTemplate().getSessionFactory().getCurrentSession();
    Userrole uRole = new Userrole();
    uRole.setIsactive("1");
    uRole.setRole(role);
    uRole.setUser(user);        
    session.save(uRole);
    session.flush();        
}


public void insertUserProfile(User user) {
    Session session = getHibernateTemplate().getSessionFactory().getCurrentSession();
    session.save(user);
}

日志:

Hibernate: 
insert 
into
    IU.Userrole
    (userroleid, createddate, deleteddate, isactive, ROLEID, USERID) 
values
    (default, ?, ?, ?, ?, ?)

05.?ub.2012 19:23:29 com.sun.faces.application.ActionListenerImpl processAction
SEVERE: org.hibernate.TransientObjectException: object references an unsaved transient instance - save the transient instance before flushing: com.iu.eblood.model.Bloodgroup
javax.faces.el.EvaluationException: org.hibernate.TransientObjectException: object references an unsaved transient instance - save the transient instance before flushing: com.iu.eblood.model.Bloodgroup
    at javax.faces.component.MethodBindingMethodExpressionAdapter.invoke(MethodBindingMethodExpressionAdapter.java:102)
    at com.sun.faces.application.ActionListenerImpl.processAction(ActionListenerImpl.java:102)
    at javax.faces.component.UICommand.broadcast(UICommand.java:315)
    at javax.faces.component.UIViewRoot.broadcastEvents(UIViewRoot.java:775)
    at javax.faces.component.UIViewRoot.processApplication(UIViewRoot.java:1267)
    at com.sun.faces.lifecycle.InvokeApplicationPhase.execute(InvokeApplicationPhase.java:82)
    at com.sun.faces.lifecycle.Phase.doPhase(Phase.java:103)
    at com.sun.faces.lifecycle.LifecycleImpl.execute(LifecycleImpl.java:118)
    at javax.faces.webapp.FacesServlet.service(FacesServlet.java:310)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:305)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
    at org.springframework.orm.hibernate3.support.OpenSessionInViewFilter.doFilterInternal(OpenSessionInViewFilter.java:198)
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:76)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:243)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
    at org.springframework.orm.hibernate3.support.OpenSessionInViewFilter.doFilterInternal(OpenSessionInViewFilter.java:198)
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:76)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:243)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:224)
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:169)
    at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:472)
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:168)
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:98)
    at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:928)
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:118)
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:407)
    at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:987)
    at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:539)
    at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:300)
    at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908)
    at java.lang.Thread.run(Thread.java:662)

Answer 1

您的问题将通过正确定义级联依赖关系或通过在保存引用的实体之前保存引用的实体来解决.定义级联是非常棘手的,因为它们的使用方式存在细微变化.

以下是如何定义级联:

@Entity
public class Userrole implements Serializable {

    private static final long serialVersionUID = 1L;

    @Id
    @GeneratedValue(strategy=GenerationType.AUTO)
    private long userroleid;

    private Timestamp createddate;

    private Timestamp deleteddate;

    private String isactive;

    //bi-directional many-to-one association to Role
    @ManyToOne(cascade = CascadeType.ALL)
    @JoinColumn(name="ROLEID")
    private Role role;

    //bi-directional many-to-one association to User
    @ManyToOne(cascade = CascadeType.ALL)
    @JoinColumn(name="USERID")
    private User user;

}

在这种情况下,每次保存,更新,删除等Userrole时,关联的角色和用户也将被保存,更新......

同样,如果您的用例要求您在更新Userrole时不修改用户或角色,那么只需在修改Userrole之前保存用户或角色

此外,双向关系具有单向所有权.在这种情况下,用户拥有Bloodgroup.因此,级联只会从用户 - >血型进行.同样,您需要将用户保存到数据库中(将其附加或使其成为非瞬态),以便将其与Bloodgroup相关联.

Answer 2

我有一个类似的问题,虽然我确保首先保存引用的实体,但它仍然失败,但同样的异常.经过数小时的调查后发现问题是因为被引用实体的"版本"列是NULL.在我的特定设置中,我首先将它插入HSQLDB(这是一个单元测试),就像这样:

INSERT INTO project VALUES (1,1,'2013-08-28 13:05:38','2013-08-28 13:05:38','aProject','aa',NULL,'bb','dd','ee','ff','gg','ii',NULL,'LEGACY','0','CREATED',NULL,NULL,1,'0',NULL,NULL,NULL,NULL,'0','0', NULL);

上面的问题是hibernate使用的版本列被设置为null,所以即使对象被正确保存,Hibernate也认为它是未保存的.当确保版本具有NON-NULL(在这种情况下为1)值时,异常消失并且一切正常.

我把它放在这里以防其他人有同样的问题,因为这花了我很长时间才弄明白,解决方案与上述完全不同.