我正在尝试创建一个UniqueName注释，作为针对create project api的定制bean验证注释：

@PostMapping("/users/{userId}/projects")
public ResponseEntity createNewProject(@PathVariable("userId") String userId,
                                       @RequestBody @Valid ProjectParam projectParam) {
    User projectOwner = userRepository.ofId(userId).orElseThrow(ResourceNotFoundException::new);

    Project project = new Project(
        IdGenerator.nextId(),
        userId,
        projectParam.getName(),
        projectParam.getDescription()
    );
    ...
  }

@Getter
@NoArgsConstructor(access = AccessLevel.PRIVATE)
class ProjectParam {

  @NotBlank
  @NameConstraint
  private String name;
  private String description;
}

@Constraint(validatedBy = UniqueProjectNameValidator.class)
@Retention(RetentionPolicy.RUNTIME)
@Target({ ElementType.FIELD })
public @interface UniqueName {

    public String message() default "already existed";

    public Class<?>[] groups() default {};

    public Class<? extends Payload>[] payload() default{};
}

public class UniqueProjectNameValidator implements ConstraintValidator<UniqueName, String> {
   @Autowired
   private ProjectQueryMapper mapper;

   public void initialize(UniqueName constraint) {
   }

   public boolean isValid(String value, ConstraintValidatorContext context) {
      // how can I get the userId info??
      return mapper.findByName(userId, value) == null;
   }
}

问题在于name字段只需要用户级别的唯一性。因此，我需要{userId}从URL字段获取进行验证。但是如何将其添加到中UniqueProjectNameValidator？还是有一些更好的方法来处理此验证？这只是大对象的一小部分，真实对象在请求处理程序中还有许多其他复杂的验证，这会使代码变得很脏。