MockMultipartHttpServletRequestBuilder request = fileUpload("/router");
request.accept(MediaType.ALL).characterEncoding("UTF-8")
.session(new MockHttpSession());
request.param("extTID", "1");
request.param("extAction", "uploadService");
request.param("extMethod", "upload");
request.param("extType", "rpc");
request.param("result", "theResult");
request.file("fileUpload", "the content of the file".getBytes());