create or replace PROCEDURE "RECUPERAR_CLAVE" (
username USUARIO.USERNAME%TYPE,
correo_consu CONSUMIDOR.CORREO_ELECTRONICO%TYPE
)
as
id_va varchar(15);
begin
select dbms_random.string('X', 10) into id_va from dual;
UPDATE usuario u set u.PASSWORD=id_va
where u.USERNAME = username
and exists(select co.CORREO_ELECTRONICO from consumidor co where
co.CORREO_ELECTRONICO=correo_consu);
end;

public boolean r_clave(String username, String correo) {
    boolean dot = false;
    try {
        StoredProcedureQuery storedProcedure = getEntityManager().createStoredProcedureQuery("RECUPERAR_CLAVE");
        storedProcedure.registerStoredProcedureParameter("username", String.class, ParameterMode.IN);
        storedProcedure.setParameter("username", username);
        storedProcedure.registerStoredProcedureParameter("correo_consu", String.class, ParameterMode.IN);
        storedProcedure.setParameter("correo_consu", correo);
        dot = true;
    } catch (Exception ex) {
        dot = false;
    }
    return dot;
}