org.hibernate.TransientObjectException: object references an unsaved transient instance - save the transient instance before flushing

Question

In my project I have User, Role, UserRole and BloodGroup entities. Firstly I take List<BloodGroup> from DB and set to User. Then I give User and Role entites to UserRole. After that I insert User to DB, then I try to insert UserRole, but I get an error. When I look to DB, the ID of BloodGroup isn't inserted in User table.

If I choose the first BloodGroup in the list, I get an error. Other options is normal.

I look at the internet, I found cascade = CascadeType.ALL, but this add same data to BloodGroup, which means I have more Arh+ BloodGroup.

The entities:

@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;

}

Controller:

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);
}

Log:

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

05.Şub.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)

Shinshina

Could you provide the code that throws the error? just to see how you are saving the instances. – Calchas

Instead of trying random things found on the internet, you should try to understand what the error means, detect where the exception is thrown, and fix the error. Show us the full stack trace and the code causing this exception to be thrown. – Godgiven

Does this answer your question? How to fix the Hibernate "object references an unsaved transient instance - save the transient instance before flushing" error – Staffer

Answer 1

your issue will be resolved by properly defining cascading depedencies or by saving the referenced entities before saving the entity that references. Defining cascading is really tricky to get right because of all the subtle variations in how they are used.

Here is how you can define cascades:

@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;

}

In this scenario, every time you save, update, delete, etc Userrole, the assocaited Role and User will also be saved, updated...

Again, if your use case demands that you do not modify User or Role when updating Userrole, then simply save User or Role before modifying Userrole

Additionally, bidirectional relationships have a one-way ownership. In this case, User owns Bloodgroup. Therefore, cascades will only proceed from User -> Bloodgroup. Again, you need to save User into the database (attach it or make it non-transient) in order to associate it with Bloodgroup.

Saurel

Answer 2

I had a similar problem and although I made sure that referenced entities were saved first it keeps failing with the same exception. After hours of investigation it turns out that the problem was because the "version" column of the referenced entity was NULL. In my particular setup i was inserting it first in an HSQLDB(that was a unit test) a row like that:

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);

The problem of the above is the version column used by hibernate was set to null, so even if the object was correctly saved, Hibernate considered it as unsaved. When making sure the version had a NON-NULL(1 in this case) value the exception disappeared and everything worked fine.

I am putting it here in case someone else had the same problem, since this took me a long time to figure this out and the solution is completely different than the above.

Lute

Hibernate always gives the worst error messages... the bane of my working life... – Bladdernose

Thank you for this answer.... same issue has just had me tearing my hair out... I was trying all sorts of transactional and cascade options only to find that the problem was a NULL version field... couldn't find anywhere else that documents this issue. – Schroder

Thank you for this answer - this was the case with me as well, when creating a user with CommandLineRunner in spring boot (also have some values with NULL, never would have guessed the object is considered as unsaved in such case) – Cordierite

Thanks, this answer just saved me a lot of headache! +1 – Bish

Answer 3

I Solved this problem adding @Cascade to the @ManyToOne attribute.

import org.hibernate.annotations.Cascade;
import org.hibernate.annotations.CascadeType;

@ManyToOne
@JoinColumn(name="BLOODGRUPID")
@Cascade({CascadeType.MERGE, CascadeType.SAVE_UPDATE})
private Bloodgroup bloodgroup;

Bearcat

Answer 4

In my case setting the referenced object to NULL in my object before the merge o save method solve the problem, in my case the referenced object was catalog, that doesn't need to be saved, because in some cases I don't have it even.

    fisEntryEB.setCatStatesEB(null);

    (fisEntryEB) getSession().merge(fisEntryEB);

Eyre

Answer 5

Instead of passing reference object passed the saved object, below is explanation which solve my issue:

//wrong
entityManager.persist(role);
user.setRole(role);
entityManager.persist(user)

//right
Role savedEntity= entityManager.persist(role);
user.setRole(savedEntity);
entityManager.persist(user)

Vincenty