Problema con Hibernate

[FiruzzZ]

Rol.hbm.xml:

<many-to-many entity-name="model.mapping.Permiso">
<column name="permiso_id" not-null="true"/>
</many-to-many>


Permiso.hbm.xml:

<class catalog="hrm" name="model.entities.Permiso" table="permiso">
<id name="id" type="long">
<column name="id"/>
<generator class="increment"/>
</id>