@应用于MultipartFile对象时，将忽略有效注释

Question

这是我的控制器。它接受带有两个字段的Multipart/form-data请求，form和file。form字段是MyObject，file字段是MultipartFile。这两个变量都用@Valid注释，因此，我希望Spring调用每个相应字段的Validator类。但是，这只发生在MyObject，而不是MultipartFile。

@RequestMapping("/api")
@RestController
public class Controller {

    private MyObjectRepository repo;
    private MyObjectValidator myObjectValidator;
    private FileValidator fileValidator;

    @Autowired
    public myObjectController(MyObjectRepository repo, MyObjectValidator myObjectValidator,
                              FileValidator fileValidator) {
        this.repo = repo;
        this.myObjectValidator = myObjectValidator;
        this.fileValidator = fileValidator;
    }

    @InitBinder("form")
    public void initMyObjectBinder(WebDataBinder binder) {
        binder.setValidator(this.myObjectValidator);
    }

    @InitBinder("file")
    public void initFileBinder(WebDataBinder binder) {
        binder.setValidator(this.fileValidator);
    }

    @PostMapping("myObject")
    @ResponseStatus(HttpStatus.CREATED)
    @ResponseBody
    public MyObject createMyObject(@RequestPart("form") @Valid MyObject myObject,
                                   @RequestPart("file") @Valid MultipartFile... file) {
        return repo.save(myObject);
    }
}

MyMyObjectValidator被触发，但MyFileValidator未被触发。这两个类都实现了SpringValidator接口<代码>MyObjectValidator。支持（类）

这里可能有什么问题？我读过类似的问题，常见的错误是在@InitBinder注释中没有使用适当的参数，或者将@InitBinder方法设置为private，而不是html" target="_blank">public，但这两者都不适用于我的情况。

这个丑陋的变通方法做了它应该做的，但它不像Spring。我在Controller.createMyObject方法中手动调用我的FileValidator，而不是让Spring通过@Valid注释自动调用它。

@PostMapping("myObject")
@ResponseStatus(HttpStatus.CREATED)
@ResponseBody
public MyObject createMyObject(@RequestPart("form") @Valid MyObject myObject,
                               @RequestPart("file") @Valid MultipartFile... file) {
    if (fileValidator.supports(file.getClass())) {
        Errors errors = new BeanPropertyBindingResult(file, "Uploaded file.");
        fileValidator.validate(file,errors);
        if (errors.hasErrors()) {
            throw new BadRequestException();
        }
    }
    return repo.save(myObject);
}

编辑：我已经包括我的Validator类请求。

import org.springframework.validation.Validator;

public abstract class AbstractValidator implements Validator {
    // One shared method here.
}

public class FileValidator extends AbstractValidator {

    public boolean supports(Class<?> aClass) { // This method is never triggered.
        boolean isSingleFile = MultipartFile.class.isAssignableFrom(aClass); // This line has a breakpoint, it is never triggered in the debugger.
        boolean isFileArray = aClass.equals(MultipartFile[].class);
        return (isSingleFile || isFileArray);
    }

    public void validate(Object o, Errors e) {
        //Several validation methods go here.
    }

public class MyObjectValidator extends AbstractValidator {

    public boolean supports(Class<?> aClass) { // This method is triggered.
        return (MyObject.class.equals(aClass)); // This line has a breakpoint, and it is always triggered in the debugger.
    }

    public void validate(Object o, Errors e) {
        // Several validation methods go here.
    }

编辑：我像NiVeR建议的那样对代码做了一些更改，删除了varargs参数，并更改了我的FileValidator.supports（类

在Controller.java：

@PostMapping("myObject")
@ResponseStatus(HttpStatus.CREATED)
@ResponseBody
public MyObject createMyObject(@RequestPart("form") @Valid MyObject myObject, @RequestPart("file") @Valid MultipartFile file) {
    return repo.save(myObject);
}

在FileValidator中。爪哇：

public boolean supports(Class<?> aClass) {
    return MultipartFile.class.isAssignableFrom(aClass);
}




Answer 1

我认为你必须在所有的Validator类中添加注释。

@Component
public class MyObjectValidator extends AbstractValidator {

    public boolean supports(Class<?> aClass) { //This method is triggered.
        return (MyObject.class.equals(aClass));
    }

    public void validate(Object o, Errors e) {
        //Several validation methods goes here.
    }
}

Answer 2

我相信这个问题与变量多部分有关 参数。在验证器的supports方法中，您正在检查多部分数组，但我怀疑这不是正确的方法。作为一个试验，我将把Multipart作为单个对象参数（并相应地更改验证器），以测试它是否以这种方式工作。