如何在 Spring 中迭代 @RequestParam？

Question

I'm building an API in Spring and I have a quick question:

I want to perform checks on these parameters below to see whether they contain values, before carrying out some logic on them.

I'm new to Spring - is there anyway to do "get" out these values into some sort of data structure so I can perform my checks?

        @RequestParam(value = "video") MultipartFile video,
        @RequestParam(value = "pictureOne") MultipartFile pictureOne,
        @RequestParam(value = "pictureTwo") MultipartFile pictureTwo,
        @RequestParam(value = "pictureThree") MultipartFile pictureThree,
        @RequestParam(value = "pictureFour", required = false) MultipartFile pictureFour,
        @RequestParam(value = "pictureFive", required = false) MultipartFile pictureFive,
        @RequestParam(value = "pictureSix",  required = false) MultipartFile pictureSix,
        @RequestParam(value = "pictureSeven", required = false) MultipartFile pictureSeven,
        @RequestParam(value = "pictureEight", required = false) MultipartFile pictureEight,
        @RequestParam(value = "pictureNine", required = false) MultipartFile pictureNine,
        @RequestParam(value = "pictureTen", required = false) MultipartFile pictureTen)

Answer 1

If you want to perform validation for all this values and close it in structure I recommend to create DTO object and put all variables as fields, ex:

public class FilesDto{
    private MultipartFile video;
    private MultipartFile photos[];
}
//Getters setters...

Then in your Controller

@Autowired
private SomeValidator someValidator;

@RequestMapping(method = RequestMethod.POST)
public void savePhotos(@Valid FilesDto filesDto) {
    ....
}

@InitBinder("filesDto")
protected void initBinde(WebDataBinder binder) {
    binder.setValidator(someValidator);
}

Where someValidator is class that implements Validator interface. According to @mbridges in comment, I also strongly recommend to use array instead of listing all parameters.