Apache Commons File upload with Spring MVC and Plupload

I am trying to get plupload to work with spring mvc. I know I am returning null and that will not give me any success or error messages on plupload.

Questions I have at this point:

1) What is best practice for saving files coming from an HTML5 file uploader. Since the file is Multipart I am not sure how to save it properly?

2) Eventually I plan to pass a folder path to the controller, what would be best practice to handle paths, but at the same time protect against misuse?

@Controller
@RequestMapping(value = "/upload")
public class UploadController {
    @RequestMapping(method = RequestMethod.POST)
    public String  uploadItem(@RequestBody MultipartFile file,
                           @RequestParam String name,
                           @RequestParam(required = false, defaultValue = "-1") int chunks,
                           @RequestParam(required = false, defaultValue = "-1") int chunk) {

        System.err.println("Original Name: " + file.getOriginalFilename());
       return null;
    }
}

Partial Example