Problems saving more than one object of the same class

JBond · **Posted:** Wed Feb 01, 2006 2:17 pm

Hi,

I have a HSQLDB (version 1.8) with 3 tables (Spiel, Satz, Zug).
There are one-to-many-relations between Spiel and Satz and between Satz and Zug.

The database works fine with Hibernate (version 3.1) except for one problem.

In a normal execution of the main programm, one Spiel-object is created, then a Satz-object which is related to the Spiel-object, and then some Zug-objects that are related to this Satz-object.

This works fine as long as I try to only save one Satz-object.
When I try to create a second Satz-object, I get:

Code:

org.hibernate.exception.GenericJDBCException: Could not execute JDBC batch update
   at org.hibernate.exception.SQLStateConverter.handledNonSpecificException(SQLStateConverter.java:91)
   at org.hibernate.exception.SQLStateConverter.convert(SQLStateConverter.java:79)
   at org.hibernate.exception.JDBCExceptionHelper.convert(JDBCExceptionHelper.java:43)
   at org.hibernate.jdbc.AbstractBatcher.executeBatch(AbstractBatcher.java:202)
   at org.hibernate.engine.ActionQueue.executeActions(ActionQueue.java:230)
   at org.hibernate.engine.ActionQueue.executeActions(ActionQueue.java:140)
   at org.hibernate.event.def.AbstractFlushingEventListener.performExecutions(AbstractFlushingEventListener.java:296)
   at org.hibernate.event.def.DefaultFlushEventListener.onFlush(DefaultFlushEventListener.java:27)
   at org.hibernate.impl.SessionImpl.flush(SessionImpl.java:980)
   at org.hibernate.impl.SessionImpl.managedFlush(SessionImpl.java:353)
   at org.hibernate.transaction.JDBCTransaction.commit(JDBCTransaction.java:106)
   at vierGewinnt.database.DAO.speichereSatz(DAO.java:250)
   at vierGewinnt.database.DAO.main(DAO.java:101)

Zug-, and Spiel-objects can be saved without any problems, but everytime I try to save a 2nd Satz-object, this error occurs.

The mapping file:

Code:

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

<hibernate-mapping>

   <class name="vierGewinnt.database.Satz" table="SATZ">
      <id name="satzId" column="satzId" type="long">
         <generator class="increment" />
      </id>
      <property name="satzNr" type="long"/>
      <property name="sieger" />

      <many-to-one name="spiel" class="vierGewinnt.database.Spiel"
         column="spielID" />

      <set name="zuege" table="ZUEGE" lazy="false">
         <key column="satzId" />
         <one-to-many class="vierGewinnt.database.Zug" />
      </set>
   </class>

</hibernate-mapping>

Satz.java

Code:

package vierGewinnt.database;

import java.io.Serializable;
import java.util.HashSet;
import java.util.Set;

public class Satz implements Serializable
{ 
   private Long satzId;
    
   private Long satzNr;
    
   private int sieger;
    
   private Spiel spiel;
   
   private Set zuege ;
    
    
   public Satz() {
      zuege = new HashSet();
   }

Getters and Setters

hashCode() and equals()
}

part of the DAO.java

Code:

   public void speichereSatz(Long spielId, Long satznr, int sieger) 
   {
      //Satzdaten speichern
      Session session = HibernateUtil.getSessionFactory().getCurrentSession();
      Satz satz = null;
      Spiel spiel = null;
      Transaction tx = null;
      try {
         tx = session.beginTransaction();
         spiel = (Spiel)session.createCriteria(Spiel.class)
         .add(Restrictions.eq("spielId",spielId))
         .uniqueResult();
         satz = new Satz();
         satz.setSpiel(spiel); //Beziehung zum Spiel setzen
         satz.setSatzNr(satznr);
         satz.setSieger(sieger);      
         session.save(satz);
         tx.commit();
      } catch (HibernateException e) {
         if (tx!=null) tx.rollback();
         System.out.println("Fehler beim Speichern des Satzes");
      }
}

Any ideas?

Thanks in advance...

Greetings from Germany,
JBond

fdurden · **Joined:** Thu Nov 17, 2005 1:44 pm **Posts:** 6

Where's the mapping for the Spiel table?

JBond · **Posted:** Wed Feb 01, 2006 6:10 pm

Spiel.hbm.xml

Code:

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

<hibernate-mapping>

   <class name="vierGewinnt.database.Spiel" table="SPIEL">
      <id name="spielId" column="spielId" type="long">
         <generator class="increment" />
      </id>
      <property name="start" />
      <property name="ende" />
      <property name="spieler1" />
      <property name="spieler2" />
      <property name="sieger" />

      <set name="saetze" table="SATZ" lazy="false">
         <key column="satzId" />
         <one-to-many class="vierGewinnt.database.Satz" />
      </set>
      
   </class>

</hibernate-mapping>

but I don't think, that it has something to do with the Spiel-table, because I tried the whole preocedure without any association between Spiel und Satz - and the same error occured...

LaLiLuna · **Posted:** Wed Feb 01, 2006 6:16 pm

may be a bug in the hashCode or equal method. You will probably not need to implement them.

Please post your complete code.
Regards Sebastian

JBond · **Posted:** Wed Feb 01, 2006 6:56 pm

I implemented the equals and hashCode methods after the 1st occurance of this error, so they can't be the cause...

the whole Satz.java

Code:

package vierGewinnt.database;

import java.io.Serializable;
import java.util.HashSet;
import java.util.Set;

public class Satz implements Serializable
{ 
   private Long satzId;
    
   private Long satzNr;
    
   private int sieger;
    
   private Spiel spiel;
   
   private Set zuege ;
    
    
   public Satz() {
      zuege = new HashSet();
   }
   
   public Long getSatzId() 
   {
      return satzId;
   }

   private void setSatzId(Long satzId) 
   {
      this.satzId = satzId;
   }

   public Long getSatzNr() 
   {
      return satzNr;
   }

   public void setSatzNr(Long satzNr) 
   {
      this.satzNr = satzNr;
   }

   public int getSieger() 
   {
      return sieger;
   }

   public void setSieger(int sieger) 
   {
      this.sieger = sieger;
   }

   public Spiel getSpiel() 
   {
      return spiel;
   }

   public void setSpiel(Spiel spiel) 
   {
      this.spiel = spiel;
   }
   
   public Set getZuege() 
   {
      return zuege;
   }

   public void setZuege(Set zuege) 
   {
      this.zuege = zuege;
   }       
   
   public boolean equals(Object andererSatz)
   {
      if (this == andererSatz) return true;
        if ( !(andererSatz instanceof Satz) ) return false;

        final Satz satz = (Satz) andererSatz;

        if ( !satz.getSpiel().equals(this.getSpiel())) return false;
        if ( !satz.getSatzNr().equals(this.getSatzNr())) return false;
      
      return true;
   }
   
    public int hashCode() {
        int result;
        result = getSpiel().hashCode();
        result = 7 * result + getSatzNr().hashCode();
        return result;
    }

}
 

LaLiLuna · **Posted:** Wed Feb 01, 2006 7:07 pm

I cannot see something specifiq. May be Hibernate is not properly guessing the type of your sieger column. Specify it.
Another thing you might try is changing the increment generator to assigned and just assign a random number.

Did you give the full stack trace? I am just wondering if your db did not return a more detailed exception

Sebastian

PS:
instead of writing the package name everywhere you can declare the package attribute in your
<hibernate-mapping package = ....

tenwit · **Joined:** Thu Dec 23, 2004 9:08 pm **Posts:** 2008

In your DAO, you're not adding your satz to your spiel. Your Set mapping isn't inverse, so it expects to be the "master" side of the relationship. So when you commit the transaction, you're setting the satz's spielId to be spielId (in DAO.java) and implicitly emptying spiel's Satz collection (because there are no satzs in the in-memory version of spiel). These are contradictory actions and are probably causing the problem.

If Satz.setSpiel() calls spiel.getSatz().add(this), then it would work. Alternatively, you could add inverse="true" to the Satz mapping in Spiel. If you did that, you'd have to refresh spiel after saving satz, so that its getSatz() Set was correct. If you want to keep your current mapping, then don't save satz; instead, add it to spiel and save spiel.

JBond · **Posted:** Thu Feb 02, 2006 6:57 am

thx for your help - but I found the problem somewhere else...

in the Spiel.hbm.xml I had

Code:

      <set name="saetze" table="SATZ" lazy="false" >
         <key column="satzId" />
         <one-to-many class="Satz" />
      </set>

instead of

Code:

      <set name="saetze" table="SATZ" lazy="false" >
         <key column="spielId" />
         <one-to-many class="Satz" />
      </set>

damn copy and paste - took me almost a week to find that...

the rest of my code works fine - I don't need to add the Satz-object to the Set in the Spiel-object...

Thanks again and greetings from Germany,
JBond