<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN" "http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
       
<hibernate-mapping>

   <class name="Fleet" table="fleet">
   
        <id name="number" column="id">
           <generator class="sequence">
              <param name="sequence">fleet_id_seq</param>
           </generator>
        </id>
       
        <natural-id mutable="true">
           <property name="name" not-null="true"/>
        </natural-id>
       
        <set name="subFleets" table="subfleet" cascade="delete-orphan" inverse="true">
           <key column="fleet" not-null="true" on-delete="cascade"/>
           <one-to-many class="SubFleet"/>
        </set>
     
    </class>


    <class name="SubFleet" table="subfleet">
   
       <id name="number" column="id">
          <generator class="sequence">
             <param name="sequence">subfleet_id_seq</param>
          </generator>
       </id>

       <natural-id mutable="true">
          <property name="name" not-null="true"/>
          <many-to-one name="fleet" not-null="true" class="Fleet" />          
       </natural-id>
              
       <set name="vehicles" table="subfleet_vehicle" cascade="save-update">
          <key column="subfleet_id" not-null="true" />
          <many-to-many class="Vehicle" column="vehicle_id" />
       </set>
       
    </class>
   
   
    <class name="Vehicle" table="vehicle">
       
       <id name="id">
          <generator class="sequence">
             <param name="sequence">vehicle_id_seq</param>
          </generator>
       </id>
              
       <set name="subFleets" table="subfleet_vehicle" inverse="true" cascade="save-update">
          <key column="vehicle_id" not-null="true" />
          <many-to-many class="SubFleet" column="subfleet_id" />
       </set>
    </class>
</hibernate-mapping>

   
public class Fleet {

   public long number;
   public String name;
   public Set<SubFleet> subFleets;
}

   public class SubFleet {

   public long number;
   public String name;
   public Fleet fleet;
   public Set<Vehicle> vehicles;
}

public class Vehicle  {

   public long id;
   public Set<SubFleet> subFleets;
}

 
Criteria fleetCrit = session.createCriteria(Fleet.class);
      fleetCrit.setFetchMode("subFleets", FetchMode.JOIN);
      
      Criteria subFleetCrit = fleetCrit.createCriteria("subFleets");
      subFleetCrit.setFetchMode("vehicles", FetchMode.JOIN);
      
      List<Fleet> fleetList = fleetCrit.list();