Spring + Hibernate : a different object with the same identifier value was already associated with the session

Question

In my application, which uses Spring and Hibernate, I parse a CSV file and populate the db by calling handleRow() every time a record is read from the CSV file.

My domain model:

'Family' has many 'SubFamily'

'SubFamily' has many 'Locus'

a 'Locus' belongs to a 'Species'

Family <-> SubFamily <-> Locus are all bi-directional mappings.

Code:

public void handleRow(Family dummyFamily, SubFamily dummySubFamily, Locus dummyLocus) {
  //Service method which access DAO layers
  CommonService serv = ctx.getCommonService();

  boolean newFamily=false;
  Family family=serv.getFamilyByFamilyId(dummyFamily.getFamilyId());
  if(family==null){
    newFamily=true;
    family=new Family();
    family.setFamilyId(dummyFamily.getFamilyId());
    family.setFamilyIPRId(dummyFamily.getFamilyIPRId());
    family.setFamilyName(dummyFamily.getFamilyName());
    family.setFamilyPattern(dummyFamily.getFamilyPattern());
    family.setRifID(dummyFamily.getRifID());
  }

  SubFamily subFamily = family.getSubFamilyBySubFamilyId( dummySubFamily.getSubFamilyId() );
  if(subFamily==null){   
    subFamily=new SubFamily();
    subFamily.setRifID(dummySubFamily.getRifID());   
    subFamily.setSubFamilyId(dummySubFamily.getSubFamilyId());
    subFamily.setSubFamilyIPRId(dummySubFamily.getSubFamilyIPRId());
    subFamily.setSubFamilyName(dummySubFamily.getSubFamilyName());
    subFamily.setSubFamilyPattern(dummySubFamily.getSubFamilyPattern());

    family.addSubFamily(subFamily);
  }

  //use the save reference, to update from GFF handler
  Locus locus = dummyLocus;

  subFamily.addLocus(locus);

  assignSpecies(serv,locus);
  //Persist object
  if(newFamily){
    serv.createFamily(family);
  } else {
    serv.updateFamily(family);
  }
}

a Species is assigned to a Locus using following method, which simply accesses the DAO layer:

private void assignSpecies (CommonService serv, Locus locus) {
  String locusId = locus.getLocusId();
  String speciesId = CommonUtils.getLocusSpecies(locusId, ctx.getSpeciesList()).getSpeciesId();
  //Simply get Species object from DAO
  Species sp = serv.getSpeciesBySpeciesId(speciesId);
  locus.setSpecies(sp);  
}

Hibernate gives following error:

[INFO] Starting scheduled refresh cache with period [5000ms]
Hibernate: insert into species (species_id, name) values (?, ?)
Hibernate: insert into species (species_id, name) values (?, ?)
Hibernate: insert into species (species_id, name) values (?, ?)
############################ROW#####################1
SubFamiyID#######RIF0005913
Hibernate: select this_.id as id1_0_, this_.family_id as family2_1_0_, this_.rif_iD as rif3_1_0_, this_.family_name as family4_1_0_, this_.family_ipr_id as family5_1_0_, this_.family_pattern as family6_1_0_ from family this_ where this_.family_id=?
Creating NEW SubFamiyID#######RIF0005913
Hibernate: select this_.id as id3_0_, this_.species_id as species2_3_0_, this_.name as name3_0_ from species this_ where this_.species_id=?
Hibernate: insert into family (family_id, rif_iD, family_name, family_ipr_id, family_pattern) values (?, ?, ?, ?, ?)
Hibernate: insert into subfamily (sub_family_id, rif_iD, sub_family_name, sub_family_ipr_id, sub_family_pattern, family_id, sub_family_index) values (?, ?, ?, ?, ?, ?, ?)
Hibernate: insert into locus (locus_id, refTrans_id, function, species_id, sub_family_id, sub_family_index) values (?, ?, ?, ?, ?, ?)
Hibernate: update species set species_id=?, name=? where id=?
Hibernate: update subfamily set family_id=?, sub_family_index=? where id=?
Hibernate: update locus set sub_family_id=?, sub_family_index=? where id=?
############################ROW#####################2
SubFamiyID#######RIF0005913
Hibernate: select this_.id as id1_0_, this_.family_id as family2_1_0_, this_.rif_iD as rif3_1_0_, this_.family_name as family4_1_0_, this_.family_ipr_id as family5_1_0_, this_.family_pattern as family6_1_0_ from family this_ where this_.family_id=?
Hibernate: select subfamilie0_.family_id as family7_1_, subfamilie0_.id as id1_, subfamilie0_.sub_family_index as sub8_1_, subfamilie0_.id as id0_0_, subfamilie0_.sub_family_id as sub2_0_0_, subfamilie0_.rif_iD as rif3_0_0_, subfamilie0_.sub_family_name as sub4_0_0_, subfamilie0_.sub_family_ipr_id as sub5_0_0_, subfamilie0_.sub_family_pattern as sub6_0_0_, subfamilie0_.family_id as family7_0_0_ from subfamily subfamilie0_ where subfamilie0_.family_id=?
Hibernate: select locuslist0_.sub_family_id as sub5_1_, locuslist0_.id as id1_, locuslist0_.sub_family_index as sub7_1_, locuslist0_.id as id2_0_, locuslist0_.locus_id as locus2_2_0_, locuslist0_.refTrans_id as refTrans3_2_0_, locuslist0_.function as function2_0_, locuslist0_.sub_family_id as sub5_2_0_, locuslist0_.species_id as species6_2_0_ from locus locuslist0_ where locuslist0_.sub_family_id=?
Hibernate: select species0_.id as id3_0_, species0_.species_id as species2_3_0_, species0_.name as name3_0_ from species species0_ where species0_.id=?
Hibernate: select this_.id as id1_0_, this_.family_id as family2_1_0_, this_.rif_iD as rif3_1_0_, this_.family_name as family4_1_0_, this_.family_ipr_id as family5_1_0_, this_.family_pattern as family6_1_0_ from family this_ where this_.family_id=?
Hibernate: select this_.id as id3_0_, this_.species_id as species2_3_0_, this_.name as name3_0_ from species this_ where this_.species_id=?
Exception in thread "main" [INFO] Closing Compass [compass]
org.springframework.orm.hibernate3.HibernateSystemException: a different object with the same identifier value was already associated with the session: [com.bigg.nihonbare.common.domain.Species#1]; nested exception is org.hibernate.NonUniqueObjectException: a different object with the same identifier value was already associated with the session: [com.bigg.nihonbare.common.domain.Species#1]
Caused by: org.hibernate.NonUniqueObjectException: a different object with the same identifier value was already associated with the session: [com.bigg.nihonbare.common.domain.Species#1]
 at org.hibernate.engine.StatefulPersistenceContext.checkUniqueness(StatefulPersistenceContext.java:590)
 at org.hibernate.event.def.DefaultSaveOrUpdateEventListener.performUpdate(DefaultSaveOrUpdateEventListener.java:284)
 at org.hibernate.event.def.DefaultSaveOrUpdateEventListener.entityIsDetached(DefaultSaveOrUpdateEventListener.java:223)
 at org.hibernate.event.def.DefaultSaveOrUpdateEventListener.performSaveOrUpdate(DefaultSaveOrUpdateEventListener.java:89)
 at org.hibernate.event.def.DefaultSaveOrUpdateEventListener.onSaveOrUpdate(DefaultSaveOrUpdateEventListener.java:70)
 at org.hibernate.impl.SessionImpl.fireSaveOrUpdate(SessionImpl.java:507)
 at org.hibernate.impl.SessionImpl.saveOrUpdate(SessionImpl.java:499)
 at org.hibernate.engine.CascadingAction$5.cascade(CascadingAction.java:218)
 at org.hibernate.engine.Cascade.cascadeToOne(Cascade.java:268)

Any tips?

Answer 1

Use merge(). The exception means that the current session is already aware of the entity you are passing. If not, check how you have overridden hashCode() and equals() - it should return different values for different entities.