Hibernate Error in GWT

Question

I am getting a hibernate error. I am just doing a proof of concept to test for association in hibernate. I am almost sure that the error i think lies in the mapping file but i cannot figure it

The example I am using is that a USER can have many COMPUTER but a COMPUTER is only for one USER

my ModuleLoad a bit analogous to main in Java

public void onModuleLoad() 
    {
        GreetingServiceAsync S = GWT.create(GreetingService.class);
        ((ServiceDefTarget) S).setServiceEntryPoint( GWT.getModuleBaseURL() +"greet");

        Computer C1= new Computer(1,"ad");
        Computer C2= new Computer(2,"ad");
        Computer C3= new Computer(3,"ad");
        Set <Computer> S1= new HashSet();
        S1.add(C2);S1.add(C3);S1.add(C1);

        Users U1= new Users(1,S1);
        S.greetServer(U1, new AsyncCallback <Users>(){

            @Override
            public void onFailure(Throwable caught) {
                // TODO Auto-generated method stub
                Window.alert("Failure");

            }

            @Override
            public void onSuccess(Users result) {
                // TODO Auto-generated method stub
                Window.alert("Success");
            }});

    }

The Users class:

    import java.util.HashSet;
    import java.util.List;
    import java.util.Set;

    import net.sf.gilead.pojo.gwt.LightEntity;

    import com.google.gwt.user.client.rpc.IsSerializable;

    public class Users extends LightEntity implements IsSerializable
    {
        private long UserId;
        private Set <Computer> Computers=new HashSet <Computer> ();

        public Users(){}
        public Users(long userId, Set <Computer> computers) 
        {
            UserId = userId;
            Computers = computers;
        }
        public long getUserId() {
            return UserId;
        }
        public void setUserId(long userId) {
            UserId = userId;
        }
        public Set <Computer> getComputers() {
            return Computers;
        }
        public void setComputers(Set<Computer> computers) {
            Computers = computers;
        }
    }

Computer Class:

    import net.sf.gilead.pojo.gwt.LightEntity;

    import com.google.gwt.user.client.rpc.IsSerializable;

    public class Computer extends LightEntity implements IsSerializable
    {
        private long ComputerId;
        private String Description;

        public Computer(){}
        public Computer(long ComputerId,String Description)
        {
            this.ComputerId=ComputerId;
            this.Description=Description;
        }

        public long getComputerId() {
            return ComputerId;
        }
        public void setComputerId(long computerId) {
            ComputerId = computerId;
        }
        public String getDescription() {
            return Description;
        }
        public void setDescription(String description) {
            Description = description;
        }
    }

Users Mapping File:
  <?xml version="1.0"?>
        <!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
        "http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
        <!-- Generated Dec 3, 2010 5:21:42 AM by Hibernate Tools 3.4.0.Beta1 -->
        <hibernate-mapping>
            <class name="com.BiddingSystem.domain.Users" table="USERS">
                <id name="UserId" type="long">
                    <column name="USERID" />
                    <generator class="assigned" />
                </id>
                <set name="Computers" table="COMPUTER" inverse="false" lazy="true">
                    <key>
                        <column name="USERID" />
                    </key>
                    <one-to-many class="com.BiddingSystem.domain.Computer" />
                </set>
            </class>
        </hibernate-mapping>

Computer Class:

import net.sf.gilead.pojo.gwt.LightEntity;

import com.google.gwt.user.client.rpc.IsSerializable;

public class Computer extends LightEntity implements IsSerializable
{
    private long ComputerId;
    private String Description;

    public Computer(){}
    public Computer(long ComputerId,String Description)
    {
        this.ComputerId=ComputerId;
        this.Description=Description;
    }

    public long getComputerId() {
        return ComputerId;
    }
    public void setComputerId(long computerId) {
        ComputerId = computerId;
    }
    public String getDescription() {
        return Description;
    }
    public void setDescription(String description) {
        Description = description;
    }
}

Computer Mapping File:

<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
<!-- Generated Dec 3, 2010 5:21:42 AM by Hibernate Tools 3.4.0.Beta1 -->
<hibernate-mapping>
    <class name="com.BiddingSystem.domain.Computer" table="COMPUTER">
        <id name="ComputerId" type="long">
            <column name="COMPUTERID" />
            <generator class="assigned" />
        </id>
        <property name="Description" type="java.lang.String">
            <column name="DESCRIPTION" />
        </property>
    </class>
</hibernate-mapping>

Hibernate Configuration File:

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE hibernate-configuration PUBLIC
        "-//Hibernate/Hibernate Configuration DTD 3.0//EN"
        "http://hibernate.sourceforge.net/hibernate-configuration-3.0.dtd">
<hibernate-configuration>
    <session-factory>
        <property name="hibernate.connection.driver_class">org.postgresql.Driver</property>
        <property name="hibernate.connection.url">jdbc:postgresql://localhost/postgres</property>
        <property name="hibernate.connection.username">postgres</property>
        <property name="hibernate.connection.password">noor</property>
        <property name="hibernate.connection.pool_size">10</property>
        <property name="show_sql">true</property>
        <property name="hibernate.dialect">org.hibernate.dialect.PostgreSQLDialect</property>
        <property name="hibernate.hbm2ddl.auto">update</property>
        <property name="current_session_context_class">thread</property> 
        <mapping resource="com/BiddingSystem/domain/Users.hbm.xml"/>
        <mapping resource="com/BiddingSystem/domain/Computer.hbm.xml"/>
    </session-factory>
</hibernate-configuration>

Server implementation to save the to the database:

import java.util.ArrayList;
import java.util.List;

import net.sf.gilead.core.PersistentBeanManager;
import net.sf.gilead.core.hibernate.HibernateUtil;
import net.sf.gilead.core.store.stateless.StatelessProxyStore;
import net.sf.gilead.gwt.PersistentRemoteService;

import org.hibernate.Query;
import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.Transaction;
import org.hibernate.cfg.Configuration;

import com.BiddingSystem.client.GreetingService;

import com.BiddingSystem.domain.Users;


import com.google.gwt.user.server.rpc.RemoteServiceServlet;
public class GreetingServiceImpl extends PersistentRemoteService implements GreetingService 
{

    private static final long serialVersionUID = 1L;
    private HibernateUtil gileadHibernateUtil = new HibernateUtil();
    public GreetingServiceImpl ()
    {
         gileadHibernateUtil.setSessionFactory(com.BiddingSystem.server.HibernateUtil.getSessionFactory());

                PersistentBeanManager persistentBeanManager = new PersistentBeanManager();
                persistentBeanManager.setPersistenceUtil(gileadHibernateUtil);
                persistentBeanManager.setProxyStore(new StatelessProxyStore());

                setBeanManager(persistentBeanManager);
    }

    public Users greetServer(Users S) 
    {
        Session session = gileadHibernateUtil.getSessionFactory().openSession();
        Transaction tr= session.beginTransaction();
        session.save(S);
        tr.commit();
        session.close();
         return S;
      }


}

The Error I am getting:

Caused by: org.hibernate.StaleStateException: Batch update returned unexpected row count from update [0]; actual row count: 0; expected: 1
    at org.hibernate.jdbc.Expectations$BasicExpectation.checkBatched(Expectations.java:85)
    at org.hibernate.jdbc.Expectations$BasicExpectation.verifyOutcome(Expectations.java:70)
    at org.hibernate.jdbc.BatchingBatcher.checkRowCounts(BatchingBatcher.java:90)
    at org.hibernate.jdbc.BatchingBatcher.doExecuteBatch(BatchingBatcher.java:70)
    at org.hibernate.jdbc.AbstractBatcher.executeBatch(AbstractBatcher.java:268)
    at org.hibernate.engine.ActionQueue.executeActions(ActionQueue.java:263)
    at org.hibernate.engine.ActionQueue.executeActions(ActionQueue.java:183)
    at org.hibernate.event.def.AbstractFlushingEventListener.performExecutions(AbstractFlushingEventListener.java:321)
    at org.hibernate.event.def.DefaultFlushEventListener.onFlush(DefaultFlushEventListener.java:51)
    at org.hibernate.impl.SessionImpl.flush(SessionImpl.java:1206)
    at org.hibernate.impl.SessionImpl.managedFlush(SessionImpl.java:375)
    at org.hibernate.transaction.JDBCTransaction.commit(JDBCTransaction.java:137)
    at com.BiddingSystem.server.GreetingServiceImpl.greetServer(GreetingServiceImpl.java:44)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
    at java.lang.reflect.Method.invoke(Method.java:597)
    at net.sf.gilead.gwt.PersistentRemoteService.processCall(PersistentRemoteService.java:174)
    ... 21 more

Users Mapping File:

<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
<!-- Generated Dec 3, 2010 5:21:42 AM by Hibernate Tools 3.4.0.Beta1 -->
<hibernate-mapping>
    <class name="com.BiddingSystem.domain.Users" table="USERS">
        <id name="UserId" type="long">
            <column name="USERID" />
            <generator class="assigned" />
        </id>
        <set name="Computers" table="COMPUTER" inverse="false" lazy="true">
            <key>
                <column name="USERID" />
            </key>
            <one-to-many class="com.BiddingSystem.domain.Computer" />
        </set>
    </class>
</hibernate-mapping>

The other file are sure to be good as I have tested them without hibernate

If anyone can help, it would be great

Answer 1

With the assigned generator in hibernate, you need to choose a different unsaved-value to tell hibernate to determine whether to INSERT or UPDATE. The default implementation looks to see if the id column is null. Since you're assigning the manually, even unsaved entities will have an id, and Hibernate will try to do an UPDATE instead of an INSERT.

Read the ID section (specifically 5.1.2.2.5) of the Hibernate documentation

Answer 2

Make sure you don't have any triggers for the table that are messing with the insert/update. It sometimes happen that the trigger overrides the result of the insert, which deceives hibernate into thinking the insert was not successful.