I'm using Hibernate annotations and have a VERY basic data object:

import java.io.Serializable;

import javax.persistence.Entity;
import javax.persistence.Id;


@Entity
public class State implements Serializable {
/**
 * 
 */
private static final long serialVersionUID = 1L;

@Id
private String stateCode;

private String stateFullName;

public String getStateCode() {
    return stateCode;
}
public void setStateCode(String stateCode) {
    this.stateCode = stateCode;
}
public String getStateFullName() {
    return stateFullName;
}
public void setStateFullName(String stateFullName) {
    this.stateFullName = stateFullName;
}   

}

and am trying to run the following test case:

public void testCreateState(){
    Session s = HibernateUtil.getSessionFactory().getCurrentSession();

    Transaction t = s.beginTransaction();

    State state = new State();
    state.setStateCode("NE");
    state.setStateFullName("Nebraska");

    s.save(s);

    t.commit();

}

and get an

org.hibernate.MappingException: Unknown entity: $Proxy2
    at org.hibernate.impl.SessionFactoryImpl.getEntityPersister(SessionFactoryImpl.java:628)
    at org.hibernate.impl.SessionImpl.getEntityPersister(SessionImpl.java:1366)
    at org.hibernate.event.def.AbstractSaveEventListener.saveWithGeneratedId(AbstractSaveEventListener.java:121)
    ....

I haven't been able to find anything referencing the $Proxy part of the error - and am at a loss.. Any pointers to what I'm missing would be greatly appreciated.

hibernate.cfg.xml

<property name="hibernate.connection.driver_class">org.hsqldb.jdbcDriver</property>
<property name="connection.url">jdbc:hsqldb:hsql://localhost/xdb</property>
<property name="connection.username">sa</property>
<property name="connection.password"></property>

<property name="current_session_context_class">thread</property>

<property name="dialect">org.hibernate.dialect.HSQLDialect</property>

<property name="show_sql">true</property>

<property name="hbm2ddl.auto">update</property>

<property name="hibernate.transaction.factory_class">org.hibernate.transaction.JDBCTransactionFactory</property>

<mapping class="com.test.domain.State"/>

in HibernateUtil.java

public static SessionFactory getSessionFactory(boolean testing ) {

    if ( sessionFactory == null ){
        try {


            String configPath = HIBERNATE_CFG;


            AnnotationConfiguration config = new AnnotationConfiguration();
            config.configure(configPath);
            sessionFactory = config.buildSessionFactory();
        } catch (Exception e){
            e.printStackTrace();
            throw new ExceptionInInitializerError(e);
        }
    }

    return sessionFactory;
}