class User{
    String name;
    int age;
    ......
}



<hibernate-mapping>
    <class name="name"/>
    ......
<hibernate-mapping>

public class MyUserType implements UserType {

   private static final int[] SQL_TYPES = {Types.VARCHAR};

   public int[] sqlTypes() {
      // TODO Auto-generated method stub
      return SQL_TYPES;
   }

   public Class returnedClass() {
      // TODO Auto-generated method stub
      return int.class;
   }


   public Object nullSafeGet(ResultSet resultSet, String[] names, Object owner) throws HibernateException, SQLException {
      if(resultSet.wasNull())
         return null;
      String string = resultSet.getString(names[0]);
   
      return new Integer(string);
   }

   public void nullSafeSet(PreparedStatement st, Object value, int index) throws HibernateException, SQLException {
      if(value == null){
         st.setNull(index, Types.VARCHAR);
      }else{
         Integer date = (Integer)value;
         st.setString(index, date.toString());
      }   
   }
   
   ......

}