@Test
public void resolveViewNameWithRequestParameter() throws Exception {
request.addParameter("format", "xls");
Map<String, MediaType> mapping = Collections.singletonMap("xls", MediaType.valueOf("application/vnd.ms-excel"));
ParameterContentNegotiationStrategy paramStrategy = new ParameterContentNegotiationStrategy(mapping);
viewResolver.setContentNegotiationManager(new ContentNegotiationManager(paramStrategy));
ViewResolver viewResolverMock = mock(ViewResolver.class);
viewResolver.setViewResolvers(Collections.singletonList(viewResolverMock));
viewResolver.afterPropertiesSet();