@Test public void testFilter() throws Exception { FilterConfig config = mockConfig("myuser"); StaticUserFilter suf = new StaticUserFilter(); suf.init(config); ArgumentCaptor<HttpServletRequestWrapper> wrapperArg = ArgumentCaptor.forClass(HttpServletRequestWrapper.class); FilterChain chain = mock(FilterChain.class); suf.doFilter(mock(HttpServletRequest.class), mock(ServletResponse.class), chain); Mockito.verify(chain).doFilter(wrapperArg.capture(), Mockito.<ServletResponse>anyObject()); HttpServletRequestWrapper wrapper = wrapperArg.getValue(); assertEquals("myuser", wrapper.getUserPrincipal().getName()); assertEquals("myuser", wrapper.getRemoteUser()); suf.destroy(); }