@Test public void test() { MockHttpServletRequestBuilder parent = new MockHttpServletRequestBuilder(HttpMethod.GET, "/"); parent.characterEncoding("UTF-8"); Object result = new MockMultipartHttpServletRequestBuilder("/fileUpload").merge(parent); assertNotNull(result); assertEquals(MockMultipartHttpServletRequestBuilder.class, result.getClass()); MockMultipartHttpServletRequestBuilder builder = (MockMultipartHttpServletRequestBuilder) result; MockHttpServletRequest request = builder.buildRequest(new MockServletContext()); assertEquals("UTF-8", request.getCharacterEncoding()); }