public @ResponseBody
WebResponse<Boolean> updateEUSettings(final Locale locale,
@Validated @ModelAttribute final EUPSettingsWrapper endUserPortalSettingsWrapper) {
}

private String label;
private MultipartFile logo;

public @ResponseBody
WebResponse<Boolean> updateEUSettings(final Locale locale,
@Validated @RequestBody final EUPSettingsWrapper endUserPortalSettingsWrapper,
@RequestParam(value = "file1", required = true) final MultipartFile logo) {
endUserPortalSettingsWrapper.setLogo(logo);

getMockMvc().perform(fileUpload(uri).file(logo)
                        .accept(MediaType.APPLICATION_JSON)
                        .content(JSONUtils.toJSON(wrapper))
                        .contentType(MediaType.MULTIPART_FORM_DATA))
                        .andExpect(status().isOk());

org.springframework.web.HttpMediaTypeNotSupportedException: Content type 'multipart/form-data' not supported

<bean id="multipartResolver"
    class="org.springframework.web.multipart.commons.CommonsMultipartResolver" />

@ResponseBody
public WebResponse<Boolean> updateEUSettings(final Locale locale, @Valid final EUPSettingsWrapper endUserPortalSettingsWrapper,
                                             @RequestParam(value = "file1", required = true) final MultipartFile logo) {


}

getMockMvc().perform(fileUpload(uri).file("file1", "some-content".getBytes())
                        .param("someEuSettingsProperty", "someValue")
                        .param("someOtherEuSettingsProperty", "someOtherValue")
                        .accept(MediaType.APPLICATION_JSON)
                        .contentType(MediaType.MULTIPART_FORM_DATA))
                        .andExpect(status().isOk());

@RequestMapping(value = "/uploadStuff", method = RequestMethod.POST)
public MyViewDto doStuff(@RequestPart("json") @Valid MyDto dto,
                         @RequestPart("file") MultipartFile file) { ... }

MockMultipartFile jsonFile = new MockMultipartFile("json", "",
            "application.json, "{}".getBytes());
MockMultipartFile dataFile = new MockMultipartFile("file", "foo.zip", "application/octet-stream", bytes);

mockMvc.perform(fileUpload("/uploadStuff")
            .file(dataFile)
            .file(jsonFile))
            .andExpect(status().isOk());