I have 3 classes : Resource, Role and Permission

Resource: id, date
Role: name
Permission: id, role, permission

Role is a subclass of Resource.

Permission contains Resource and Role.

I have a problem with my mapping file. Could you help me? I don't know
how to represent that.

<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC
"-//Hibernate/Hibernate Mapping DTD//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-2.0.dtd">
<hibernate-mapping>

<class name="Permission" table="DWPermission">
<id name="id" column="id" type="long">
<generator class="native"/>
</id>

<component name="role" class="Role">
<property name="idRole" type="long"/>
</component>

<component name="ressource" class="Resources">
<property name="idResource" type="long"/>
</component>
</class>

<class name="Resources" table="DWResources">
<id name="id" column="id" type="long">
<generator class="native"/>
</id>

<property name="date" type="timestamp"/>
<joined-subclass name="Role" table="DWRole">
<key column="resourceId"/>
<property name="name" type="string" unique="true"/>
</joined-subclass>

</class>

</hibernate-mapping>

Thanks

reread the documentation, either :
- use component but do not map role and Resource as Entity (<class>).
- use Entity and map the link with a one-to-one or another association.

I don't think components can be subclasses, then the second solution is the one you need.