Not-null property references a null or transient value

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN" "http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
<hibernate-mapping>
  <class name="classes.c_pedido_quarto" table="pedido_quarto">
      
       <id name="c_pedido_quarto_id"  type="int">    
        <generator class="identity"/>    
        </id>    
        <many-to-one 
        name="apartamento" 
        column="apartamento" 
        class="classes.c_apartamentos"
         />
         <many-to-one
column="hospede"
name="hospede"
class="classes.c_hospedes"
cascade="all"
not-null="true"

        />
        <many-to-one
        column="ehospede"
        name="ehospede"
       class="classes.c_entrada_hospede"
  not-null="true"
       cascade="all"
     
        />
        <many-to-one 
        column="rhospede"
        name="rhospede"
        class="classes.c_reserva_hospede"
 not-null="true"
       cascade="all"
      
        />
      <many-to-one 
        column="fechamento"
        name="fechamento"
        class="classes.c_fechamento"
        cascade="all"
        not-null="true"
      
        />
<set name="l_chamada" inverse="true" cascade="all" lazy="false"> 
<key column="c_pedido_quarto_id"/> 
<one-to-many class="classes.c_chamada"/> 
</set> 
<set name="l_consumo" inverse="true" cascade="all" lazy="false"> 
<key column="c_pedido_quarto_id"/> 
<one-to-many class="classes.c_consumo"/> 
</set> 
  </class>
</hibernate-mapping>

public void Completa()
{
    try{
        
        
        getCampos(); 
        // Inseri reserva do hospede
        pquarto.setRhospede(rehospede);   
        DAOGenerico dao = new DAOGenerico(pquarto);
        dao.inseri();
        dispose();
    }catch(Exception erro)
    {
        JOptionPane.showMessageDialog(null,"Completa() :"+erro);
        System.out.println(erro);
    }
}