org.hibernate.NonUniqueObjectException when saving a list of child objects

Question

I need to save several child objects when creating the parent object. Ideally, I want to save them in one transaction, however, I keep getting an org.hibernate.NonUniqueObjectException: a different object with the same identifier value was already associated with the session.

In this example, a SubDiscipline has many SubdisciplinePlayers.

I feel that there's something wrong with the mapping

POJOs:

Subdiscipline.java

public class Subdiscipline {

    private int id;
    private int disciplineId;
    private String name;
    private List<SubdisciplinePlayer> subdisciplinePlayers;

    public Subdiscipline() {
    }

    //standard constructors, getter & setters...
}

SubdisciplinePlayers.java

public class SubdisciplinePlayer implements Serializable {

    private int idPlayers;
    private int disciplineId;
    private int subDisciplineId;
    private int players;
    private int minPlayers;
    private int maxPlayers;

    private Subdiscipline subdiscipline;

    public SubdisciplinePlayer() {
    }
    //standard constructors, getter & setters...
}

Main.java:

public class Main {

    @SuppressWarnings("unchecked")
    public static void main(String[] args) {

        SessionFactory sf = HibernateUtil.getSessionFactory();
        Session session = sf.openSession();
        session.beginTransaction();

        Subdiscipline sd = new Subdiscipline("soccer_" + (new Date()).getTime(), new Date(), new Date(), new Status(1) );
        sd.setDisciplineId(4);
        session.save(sd);

        SubdisciplinePlayer sdp = new SubdisciplinePlayer();
        sdp.setDisciplineId(sd.getDisciplineId());
        sdp.setSubDisciplineId(sd.getId());
        sdp.setSubdiscipline(sd);
        sdp.setIdPlayers(555);

        SubdisciplinePlayer sdp2 = new SubdisciplinePlayer();
        sdp2.setDisciplineId(sd.getDisciplineId());
        sdp2.setSubDisciplineId(sd.getId());
        sdp2.setSubdiscipline(sd);
        sdp2.setIdPlayers(457);

        sd.setSubdisciplinePlayers(new ArrayList<SubdisciplinePlayer>());
        sd.getSubdisciplinePlayers().add(sdp);
        sd.getSubdisciplinePlayers().add(sdp2);

        session.save(sd);

        session.getTransaction().commit();
        session.close();

    }
}

Mappings

Subdiscipline Mapping

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE hibernate-mapping
PUBLIC "-//Hibernate/Hibernate Mapping DTD//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">

<hibernate-mapping>
    <class name="net.viralpatel.hibernate.Subdiscipline" table="sub_discipline">
        <id name="id" column="sub_dis_id" unsaved-value="0">
            <generator class="increment"/>
        </id>
        <property name="disciplineId" column="dis_id" type="int"/>
        <property name="name" column="sub_discipline" type="string"/>           
        <bag name="subdisciplinePlayers" table="sdis_players" inverse="true" cascade="all">
            <key column="sub_dis_id" />
            <one-to-many class="net.viralpatel.hibernate.SubdisciplinePlayer" />
        </bag>

    </class>
</hibernate-mapping>

SubdisciplinePlayer Mapping

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE hibernate-mapping
PUBLIC "-//Hibernate/Hibernate Mapping DTD//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">

<hibernate-mapping>
    <class name="net.viralpatel.hibernate.SubdisciplinePlayer" table="sdis_players">
        <composite-id>
            <key-property name="disciplineId" column="dis_id" type="int"/>
            <key-property name="subDisciplineId" column="sub_dis_id" type="int" />
        </composite-id>
        <property name="idPlayers" column="id_players" type="int"/>
        <property name="players" column="players" type="int"/>
        <property name="minPlayers" column="min_players" type="int"/>
        <property name="maxPlayers" column="max_players" type="int"/>
        <many-to-one name="subdiscipline" class="net.viralpatel.hibernate.Subdiscipline" cascade="none" insert="false" update="false">
            <column name="sub_dis_id"/>
        </many-to-one>
    </class>
</hibernate-mapping>

Exception thrown

Exception in thread "main" org.hibernate.NonUniqueObjectException: a different object     with the same identifier value was already associated with the session:     [net.viralpatel.hibernate.SubdisciplinePlayer#net.viralpatel.hibernate.SubdisciplinePlayer@1cd7e9c3]

Learner · Accepted Answer · 2014-10-01 05:41:41Z

3

You have declared composite key with fields disciplineId & subDisciplineId for your entity SubdisciplinePlayer.

Now in your program you are creating 2 instances of SubdisciplinePlayer with same composite id.

SubdisciplinePlayer sdp = new SubdisciplinePlayer();
sdp.setDisciplineId(sd.getDisciplineId());
sdp.setSubDisciplineId(sd.getId());

SubdisciplinePlayer sdp2 = new SubdisciplinePlayer();
sdp2.setDisciplineId(sd.getDisciplineId());
sdp2.setSubDisciplineId(sd.getId());

So when you call Session.save(sd), hibernate observed that you are trying to save 2 instances of SubdisciplinePlayer and throwing the exception as :

org.hibernate.NonUniqueObjectException: a different objectwith the same identifier 
value was already associated with the session:     
[net.viralpatel.hibernate.SubdisciplinePlayer#
net.viralpatel.hibernate.SubdisciplinePlayer@1cd7e9c3]

To fix the issue just make sure that the composite id of SubdisciplinePlayer should have different values as primary key should be unique.

answered Oct 1, 2014 at 5:41

Learner

21.5k56 gold badges177 silver badges296 bronze badges

Sign up to request clarification or add additional context in comments.

1 Comment

Ramses Over a year ago

Now that you point this out, seems obvious, thanks. The problem is that the field idPlayers is an autoincrement field, part of the composite key of SubDisciplinePlayers. How can I modify the mapping to reflect this?

Community · Accepted Answer · 2017-05-23 12:08:44Z

1

Please use merge instead of save when you are trying with second time save.

   sd.setSubdisciplinePlayers(new ArrayList<SubdisciplinePlayer>());
   sd.getSubdisciplinePlayers().add(sdp);
   sd.getSubdisciplinePlayers().add(sdp2);
   session.merge(sd);

I listed out more ref for you.

Ref 1

Ref 2

edited May 23, 2017 at 12:08

CommunityBot

11 silver badge

answered Oct 1, 2014 at 5:07

ashokhein

1,05814 silver badges38 bronze badges

Collectives™ on Stack Overflow

org.hibernate.NonUniqueObjectException when saving a list of child objects

POJOs:

Subdiscipline.java

SubdisciplinePlayers.java

Main.java:

Mappings

Subdiscipline Mapping

SubdisciplinePlayer Mapping

Exception thrown

2 Answers 2

1 Comment

Comments

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

POJOs:

Subdiscipline.java

SubdisciplinePlayers.java

Main.java:

Mappings

Subdiscipline Mapping

SubdisciplinePlayer Mapping

Exception thrown

2 Answers 2

1 Comment

Comments

Your Answer

Sign up or log in

Post as a guest

Linked

Related