Mockito return the value from the response

An example:
private HttpServletRequest request = mock(HttpServletRequest.class);
    private HttpServletResponse response = mock(HttpServletResponse.class);

    @Test
    public void testAuthz() throws Exception {
        AuthorizationEndpoint endpoint = new AuthorizationEndpoint();
        when(request.getParameter("response_type")).thenReturn(ResponseType.CODE.toString());
        when(request.getParameter("client_id")).thenReturn("test_id");
        when(request.getParameter("redirect_uri")).thenReturn("http://localhost");

        final ArrayList values = new ArrayList();
        doAnswer(new Answer