hibernate映射继承关系

DOClass{   
   id   
}   
ClassA extends DOClass{   
    A1   
}   
   
ClassC extends ClassA{   
    C1   
}   
   
ClassD extends ClassA{   
    D1   
}   
   
ClassG extends ClassD{   
    G1   
}   
   
ClassH extends ClassD{   
    H1   
}   
   
ClassB extends DOClass{   
    B1   
}   
   
ClassE extends ClassB{   
    E1,e2,e3,e4,e5,e6   
}   
   
ClassF extends ClassB{   
    F1,f2,f3,f4,f5,f6,f7   
}   
   
TABLE_A {ID(PK)，A_TYPE(discriminator)，A1,C1,D1,G1,H1}   
TABLE_B {ID(PK)，B1}   
TABLE_E {B_ID(PK/FK)，E1,E2,E3,E4,E5,E6}   
TABLE_F {B_ID(PK/FK)，F1,F2,F3,F4,F5,F6,F7}   
   
ClassA.hbm.xml   
<hibernate-mapping>   
    <class name=”ClassA” table=”TABLE_A” discriminator-value=”A”>   
        <id/>   
        <discriminator column=”A_TYPE” type=”string”/>   
        <property name=”a1” column=”A1”/>   
        <sub-class name=”ClassC” discriminator-value=”C”>   
            <property name=”c1” column=”C1”/>   
        </sub-class>   
<subclass name=”ClassD” discriminator-value=”D”>   
            <property name=”d1” column=”D1”/>   
            <subclass name=”ClassG” discriminator-value=”G”>   
                <property name=”g1” column=”G1”/>   
            </subclass>   
            <subclass name=”ClassH” discriminator-value=”H”>   
                <property name=”h1” column=”H1”/>   
            </subclasss>   
</subclass>   
</class>   
</hibernate-mapping>   
ClassB.hbm.xml   
<hibernate-mapping>   
    <class name=”ClassB” table=”TABLE_B”>   
        <id/>   
        <property name=”b1” column=”B1”/>   
        <joined-subclass name=”ClassE” table=”TABLE_E”>   
            <key column=”B_ID”/>   
            <property name=”e1” column=”E1”/>   
            <property name=”e2” column=”E2”/>   
            <property name=”e3” column=”E3”/>   
            <property name=”e4” column=”E4”/>   
            <property name=”e5” column=”E5”/>   
            <property name=”e6” column=”E6”/>   
        </joined-subclass>   
        <joined-subclass name=”ClassF” table=”TABLE_F”>   
            <key column=”B_ID”/>   
            <property name=”f1” column=”F1”/>   
            <property name=”f2” column=”F2”/>   
            <property name=”f3” column=”F3”/>   
            <property name=”f4” column=”F4”/>   
            <property name=”f5” column=”F5”/>   
            <property name=”f6” column=”F6”/>   
            <property name=”f7” column=”F7”/>   
        </joined-subclass>   
    </class>   
</hibernate-mapping>