How to test a filter in a java application using mockito

I have filter:

@Override
public void doFilter(ServletRequest req, ServletResponse resp, FilterChain chain) throws IOException, ServletException {
    HttpServletRequest request = (HttpServletRequest) req;
    User user = (User) request.getSession().getAttribute(Attribute.ATTRIBUTE_USER);
    if (user == null) {
        HttpServletResponse response = (HttpServletResponse) resp;
        response.sendRedirect("/controller?command=goToError");
    } else {
        chain.doFilter(req, resp);

And I have my test:

@Mock
private FilterChain filterChain;
@Mock
private HttpSession sessionTest;
@Mock
private User userTest;
@Mock
private UserFilter userFilterTest;
@Mock
private ServletResponse servletResponse;
@Mock
private ServletRequest servletRequest;

@Before
public void setUp() {
    MockitoAnnotations.initMocks(this);
}

@Test
public void testDoFilter() {
    Mockito.doReturn(userTest).when(sessionTest).getAttribute(Attribute.ATTRIBUTE_USER);
    try {
        userFilterTest.doFilter(servletRequest, servletResponse, filterChain);
        verify(filterChain).doFilter(servletRequest, servletResponse);
    } catch (IOException | ServletException e) {
        fail();
    }
}

I dont know what is the problem with my test. Writes that the method which in verify() has never been called. Please help