java - Spring中如何迭代@RequestParam？

Question

我正在 Spring 中构建一个 API，我有一个简单的问题:

我想在对下面的这些参数执行一些逻辑之前检查它们是否包含值。

我是 Spring 新手 - 有没有办法将这些值“获取”到某种数据结构中，以便我可以执行检查？

        @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

如果您想对所有这些值执行验证并在结构中关闭它，我建议创建 DTO 对象并将所有变量作为字段，例如:

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

然后在你的 Controller 中

@Autowired
private SomeValidator someValidator;

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

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

其中someValidator是实现Validator接口(interface)的类。根据评论中的@mbridges，我还强烈建议使用数组而不是列出所有参数。