ClassCastException when trying to merge an entity bean

[pjmunoz]

I get a ClassCastException when trying to merge a bean of this class:

package hormigaclub.entidades;

import javax.persistence.*;

@Entity(access = AccessType.FIELD)
@Table(name = "personas")
public class Persona extends Entidad {
private static final long serialVersionUID = 1L;

@Id(generate = GeneratorType.AUTO)
private Long id;

private Long dni;
private String apellido;
private String nombre1;
private String nombre2;
private String direccionCalle;
private Integer direccionNumero;
private String direccionDpto;
private String direccionLocalidad;
private Integer direccionCodPostal;
private String direccionProvincia;
private String telefono1;
private String telefono2;
private String email;

@OneToOne(mappedBy = "persona")
private Cliente cliente;

@OneToOne(mappedBy = "persona")
private Promotor promotor;

@OneToOne(mappedBy = "persona")
private Empleado empleado;

@OneToOne(mappedBy = "persona")
private Proveedor proveedor;

(various methods)....

}

the stacktrace is the following :

2005-09-23 14:20:26,383 DEBUG [org.hibernate.jdbc.AbstractBatcher] preparing statement
2005-09-23 14:20:26,383 DEBUG [org.hibernate.type.LongType] binding 'hormigaclub.entidades.Persona@19747ae' to parameter: 1
2005-09-23 14:20:26,383 INFO [STDOUT] java.lang.ClassCastException: hormigaclub.entidades.Persona
2005-09-23 14:20:26,384 INFO [STDOUT] at org.hibernate.type.LongType.set(LongType.java:40)
2005-09-23 14:20:26,384 INFO [STDOUT] at org.hibernate.type.NullableType.nullSafeSet(NullableType.java:63)
2005-09-23 14:20:26,384 INFO [STDOUT] at org.hibernate.type.NullableType.nullSafeSet(NullableType.java:45)
2005-09-23 14:20:26,384 INFO [STDOUT] at org.hibernate.loader.Loader.bindPositionalParameters(Loader.java:1456)
2005-09-23 14:20:26,384 INFO [STDOUT] at org.hibernate.loader.Loader.prepareQueryStatement(Loader.java:1518)
2005-09-23 14:20:26,384 INFO [STDOUT] at org.hibernate.loader.Loader.doQuery(Loader.java:638)
2005-09-23 14:20:26,384 INFO [STDOUT] at org.hibernate.loader.Loader.doQueryAndInitializeNonLazyCollections(Loader.java:221)
2005-09-23 14:20:26,384 INFO [STDOUT] at org.hibernate.loader.Loader.loadEntity(Loader.java:1695)
2005-09-23 14:20:26,384 INFO [STDOUT] at org.hibernate.loader.entity.AbstractEntityLoader.load(AbstractEntityLoader.java:46)
2005-09-23 14:20:26,384 INFO [STDOUT] at org.hibernate.loader.entity.EntityLoader.loadByUniqueKey(EntityLoader.java:85)
2005-09-23 14:20:26,384 INFO [STDOUT] at org.hibernate.persister.entity.AbstractEntityPersister.loadByUniqueKey(AbstractEntityPersister.java:1395)
2005-09-23 14:20:26,384 INFO [STDOUT] at org.hibernate.type.EntityType.loadByUniqueKey(EntityType.java:356)
2005-09-23 14:20:26,384 INFO [STDOUT] at org.hibernate.type.EntityType.resolve(EntityType.java:297)
2005-09-23 14:20:26,384 INFO [STDOUT] at org.hibernate.type.EntityType.replace(EntityType.java:206)
2005-09-23 14:20:26,385 INFO [STDOUT] at org.hibernate.type.TypeFactory.replace(TypeFactory.java:407)
2005-09-23 14:20:26,385 INFO [STDOUT] at org.hibernate.event.def.DefaultMergeEventListener.copyValues(DefaultMergeEventListener.java:262)
2005-09-23 14:20:26,385 INFO [STDOUT] at org.hibernate.event.def.DefaultMergeEventListener.entityIsDetached(DefaultMergeEventListener.java:247)
2005-09-23 14:20:26,385 INFO [STDOUT] at org.hibernate.event.def.DefaultMergeEventListener.onMerge(DefaultMergeEventListener.java:111)
2005-09-23 14:20:26,385 INFO [STDOUT] at org.hibernate.event.def.DefaultMergeEventListener.onMerge(DefaultMergeEventListener.java:60)
2005-09-23 14:20:26,385 INFO [STDOUT] at org.hibernate.impl.SessionImpl.merge(SessionImpl.java:542)
2005-09-23 14:20:26,385 INFO [STDOUT] at org.hibernate.ejb.AbstractEntityManagerImpl.merge(AbstractEntityManagerImpl.java:140)
2005-09-23 14:20:26,385 INFO [STDOUT] at org.jboss.ejb3.entity.InjectedEntityManager.merge(InjectedEntityManager.java:102)
2005-09-23 14:20:26,385 INFO [STDOUT] at hormigaclub.beans.AdmUsuariosSBBean.guardarUsuario(AdmUsuariosSBBean.java:59)
2005-09-23 14:20:26,385 INFO [STDOUT] at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
2005-09-23 14:20:26,385 INFO [STDOUT] at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
2005-09-23 14:20:26,385 INFO [STDOUT] at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
2005-09-23 14:20:26,385 INFO [STDOUT] at java.lang.reflect.Method.invoke(Method.java:585)
2005-09-23 14:20:26,385 INFO [STDOUT] at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:99)
2005-09-23 14:20:26,385 INFO [STDOUT] at org.jboss.ejb3.AllowedOperationsInterceptor.invoke(AllowedOperationsInterceptor.java:32)
2005-09-23 14:20:26,385 INFO [STDOUT] at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:88)

it seems that jboss is trying to bind the toString() method of the entity to it's id field (parameter '1') which is of type Long.
Can anyone tell me why is this happening and how to solve it?
thank you very much

[pjmunoz]

Reading again I realized that actually it's not trying to bind the toString() but the bean itself to the id, however the result is the same

[epbernard]

are all your one to one association also use Long?

[fbenvegna]

We have same error with Seam 1.2.1-GA and JBoss 4.0.5-GA.
Our problem was double assignment in @OneToOne relationship.

A a = new A();
B b = new B();
a.setB(b);
b.setA(a);

Solution:
set the the relationship only to the object that own the mapping (table with foreign key)

A a = new A(); // if A has mapping
B b = new B();
a.setB(b);
// b.setA(a);

[fbenvegna]

Sorry, but problem is coming back.
The solution is update Hibernate Core to version 3.1 or over.
It's a bug on one-to-one relationship