Hibernate mapping com subclasse e discriminator

<?xml version="1.0"?>

&lt;!DOCTYPE hibernate-mapping PUBLIC
     "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
     "http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd"&gt;

&lt;hibernate-mapping package="joy.cadastros.bo"&gt;	
	
	&lt;class name="Endereco" table="Endereco" discriminator-value="-"&gt;
		
			
			&lt;composite-id&gt;
				&lt;key-property name="id" column="id_endereco"/&gt;
				&lt;key-property name="tipo" column="tipo"/&gt;									
			&lt;/composite-id&gt;
			
			&lt;discriminator column="tipo"
			               type="string"

			 /&gt;

			&lt;property 
				name="endereco" 
				column="endereco" 
				type="string" 
				length="50" 
				not-null="true"
			/&gt;

			&lt;property name="cidade"/&gt;

			&lt;property name="bairro"/&gt;

			&lt;property name="estado"/&gt;

			&lt;property name="cep"/&gt;
	
			&lt;property name="fone1"/&gt;

			&lt;property name="fone2"/&gt;	

			&lt;property name="estadolocal"/&gt;	
			
			
			&lt;subclass name="EnderecoOrientador"
				      extends="Endereco"
				      discriminator-value="O"/&gt;		      

			
	&lt;/class&gt;
	
&lt;/hibernate-mapping&gt;