Jsf

public void getSessionBackingBean() {
        Object object = 
            FacesContext
                .getCurrentInstance()
                    .getExternalContext()
                        .getSessionMap()
                            .get("meuSessionBackingBean");
                            
        // Isso só funciona se o meuSessionBackingBean for de Sessão
        if (object != null) {
            MeuSessionBackingBean meuBean = (MeuSessionBackingBean ) object; 
            meuBean .getCampoTextoID().setValue("1000");
        }
    }