public   class  Person...
 private   int  personNumber;
 private  String personName;
 private  Set addresses= new  HashSet();
 private  Role role =  new  Role();
...
 public   class  Role...
 private   int  roleId;
 private  String roleName;

create table persons (
    personNumber integer, 
    personName VARCHAR( 255 ),
    roleId integer, 
    primary key (personNumber)
)
create table addresses (
    id integer,
    personNumber integer, 
    fullAddress VARCHAR( 255 ),
    primary key (id)
)
create table roles(
    roleId integer, 
    roleName VARCHAR( 255 ),
    primary key (roleId)
)

< class  name="Person" table="persons">

        <id name="personNumber" column="personNumber">
        </id>
        <property name="personName" column="personName"/>
        <set name="addresses" table="persons">
            <key column="personNumber"/>
            <one-to-many  class ="Address"/>
        </set>
        <many-to-one name="role"  class ="Role" column="roleId" not- null ="true"/>

    </ class >

System.out.println(Person.getRole().getRoleName());