@Controller
// @RequestMapping("/login")
public class LoginController extends HttpServlet {


    private static final long serialVersionUID = 1L;
    private String username;
    private String password;

    @Autowired
    Usuarios usuarios;


    HttpServletRequest request;
    HttpServletResponse response;

    public String getUsername() {
        return username;
    }

    public void setUsername(String username) {
        this.username = username;
    }

    public String getPassword() {
        return password;
    }

    public void setPassword(String password) {
        this.password = password;
    }

    @RequestMapping("/login")
    public ModelAndView logins() {
        ModelAndView mv = new ModelAndView("/login");
        mv.addObject(new Documento());
        return mv;
    }

    @RequestMapping("/efetuaLogin")
    public ModelAndView login(HttpServletRequest request, HttpServletResponse response) {

        boolean validacao = false;

        HttpSession sessao;

        List<Usuario> usuariosCadastrados = usuarios.lista();


        String username = request.getParameter("username");
        String password = request.getParameter("password");

        for (Usuario usuario : usuariosCadastrados) {

            String loginbd = usuario.getUsername();
            String senhabd = usuario.getPassword();

            System.out.println("username do Formulario...:" + loginbd);
            System.out.println("Senha do banco........:" + senhabd);
            System.out.println("Senha do Formulario...:" + password);
            System.out.println("username do Formulario...:" + username);

            if (username.equals(loginbd) && password.equals(senhabd)) {
                validacao = true;

            }
            if (validacao == true) {

                return new ModelAndView("/documentos");

            } else {
                return new ModelAndView("hello");

            }
        }
        return null;
    }
}

    @Service
public class LoginService {

    @PersistenceContext
      private EntityManager em;

    @Autowired
    private Usuarios usuarios;

    public List<Usuario> lista() {
      return em.createQuery("select u from Usuario u", Usuario.class).getResultList();
    }
}