Spring Controller @RequestBody with file upload is it possible?

Question

I have a Controller like this and I want to submit a form with file uploading as well as some form data like label as shown below. Also, I want to do that using @RequestBody so I can use the @Valid annotation on the wrapper as more variables will be added.

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

And my wrapper is:

public class EUPSettingsWrapper {

    private String label;
    private MultipartFile logo;
// getter , setters..etc...
}

But I would like to convert it into a @RequestBody from ModelAttributes.

The way I'm trying is by having the file upload separated as request parameter like this:

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

    endUserPortalSettingsWrapper.setLogo(logo);

    // ...
}

In my mock MVC, I am setting:

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

But I'm getting an error like this which says:

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

Does anyone have a good idea of how Multipart file uploads can be used with @RequestBody? Anything I am doing wrong above?

Answer 1

You can actually simplify your life here since all you are doing is submitting a form that contains some fields and file. You don't need @RequestBody for what you are trying to do. You can use regular Spring MVC features, so your controller method would look like:

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


}

The client that submits the request to this controller will need to have a form with enctype="multipart/form-data".

In your Spring MVC test you would write something like this:

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());