how can I solve the java.lang.ClassCastException problem

I have a class for a login and when I login I get this:

  

com.logic.Teaching can not be converted to com.logic.Docente

I have tried to assign a variable to the session, however I get this error, I always have to restart the server and I've been in this for more than 3 weeks and it's already uncomfortable.

These are my methods.

/**
 * *
 * Metodo para login de docente
 *
 * @return la pagina redireccionando al docente al index
 */
public String loginUser() {
    try {
        TypedQuery<Docente> query = entityManager.createNamedQuery("Docente.Login", Docente.class);
        query.setParameter("user", user);
        query.setParameter("password", password);
        if (query.getResultList().size() > 0) {
            FacesContext.getCurrentInstance().getExternalContext().getSessionMap().put("userTeacherSesion", query.getResultList().get(0));
            return "Views/IndexTeacher";
        }
    } catch (Exception e) {
        System.out.println(e.getMessage());
    }
    message = "usuario o password incorrecta";
    return "";
}


/**
 * *
 * metodo para obtener el id del docente
 *
 * @return El objeto con la sesion
 */
public Docente getDocenteSesion() {
    return (Docente) FacesContext.getCurrentInstance().getExternalContext().getSessionMap().get("userTeacherSesion");
}

  

Caused by: java.lang.ClassCastException: com.logic.Docente can not be   cast to com.logic.Docente at   com.controller.LoginController.getDocenteSesion (LoginController.java:120)