login(formGroup: FormGroup): Observable<boolean> {
        const headers = new Headers();
        headers.append('Authorization', 'Basic xxxxxxxxxxxx')
        headers.append('Content-Type', 'application/x-www-form-urlencoded');
        let user = formGroup.get('username').value;
        let password = formGroup.get('password').value;
        const body = 'username=' + user + '&password=' + password + '&grant_type=password';
        return this.http.post(URIConstantes.LOGIN, body, {headers: headers})
            .map((response: Response) => {
                let token = response.json()['access_token'];
                if (token != null) {
                    this.token = token;
                    this.saveTokenToLocalStorage(token);
                    return true;
                } else {
                    // return false to indicate failed login
                    return false;
                }
            });
    }

obterNovoAccessToken(): Observable<any> {
        const headers = new Headers();
        headers.append('Content-Type', 'application/x-www-form-urlencoded')
        headers.append('Authorization', 'Basic YW5ndWxhcjpAbmd1bEByMA==')

        const body = 'grant_type=refresh_token';
        return this.http.post(URIConstantes.LOGIN, body, { headers, withCredentials: true })
          .map(response => {
              console.log(response);
              this.armazenarToken(response.json()['access_token']);
              console.log('Novo access token criado!');
          }).catch(
          response => {
            console.error('Erro ao renovar token.', response.json());
            return Promise.resolve(null);
          });
      }

@ControllerAdvice
public class RefreshTokenPostProcessor implements ResponseBodyAdvice<OAuth2AccessToken> {

    @Override
    public boolean supports(MethodParameter returnType, Class<? extends HttpMessageConverter<?>> converterType) {
        return returnType.getMethod().getName().equals("postAccessToken");
    }

    @Override
    public OAuth2AccessToken beforeBodyWrite(OAuth2AccessToken body, MethodParameter returnType,
            MediaType selectedContentType, Class<? extends HttpMessageConverter<?>> selectedConverterType,
            ServerHttpRequest request, ServerHttpResponse response) {

        HttpServletRequest req = ((ServletServerHttpRequest) request).getServletRequest();
        HttpServletResponse resp = ((ServletServerHttpResponse) response).getServletResponse();

        DefaultOAuth2AccessToken token = (DefaultOAuth2AccessToken) body;

        String refreshToken = body.getRefreshToken().getValue();
        adicionarRefreshTokenNoCookie(refreshToken, req, resp);
        removerRefreshTokenDoBody(token);

        return body;
    }

    private void removerRefreshTokenDoBody(DefaultOAuth2AccessToken token) {
        token.setRefreshToken(null);
    }

    //add token on cookie response
    private void adicionarRefreshTokenNoCookie(String refreshToken, HttpServletRequest req, HttpServletResponse resp) {
        Cookie refreshTokenCookie = new Cookie("refreshToken", refreshToken);
        refreshTokenCookie.setHttpOnly(true);
        refreshTokenCookie.setSecure(false);
        refreshTokenCookie.setPath(req.getContextPath() + "/oauth/token");
        refreshTokenCookie.setMaxAge(2592000);
        resp.addCookie(refreshTokenCookie);
    }

}