MismatchedInputException时如何设置空值？

import org.springframework.lang.Nullable;

public class MyObject {
    @Nullable
    private Integer myField;
    // getters and setters
}

import java.util.Optional;

public class MyObject {
    private Optional<Integer> myField;
    // getters and setters
}

import org.springframework.http.HttpStatus;
import org.springframework.http.ResponseEntity;
import org.springframework.web.bind.MismatchedInputException;
import org.springframework.web.bind.annotation.ControllerAdvice;
import org.springframework.web.bind.annotation.ExceptionHandler;

@ControllerAdvice
public class GlobalExceptionHandler {

    @ExceptionHandler(MismatchedInputException.class)
    public ResponseEntity<String> handleMismatchedInputException(MismatchedInputException ex) {
        return new ResponseEntity<>("Invalid input: " + ex.getMessage(), HttpStatus.BAD_REQUEST);
    }
}

import org.springframework.web.bind.WebDataBinder;
import org.springframework.web.bind.annotation.Controller;
import org.springframework.web.bind.annotation.InitBinder;

@Controller
public class MyController {

    @InitBinder
    public void initBinder(WebDataBinder binder) {
        binder.registerCustomEditor(Integer.class, new CustomNumberEditor(Integer.class, true));
    }

    // other controller methods
}

import javax.validation.constraints.NotNull;
import javax.validation.constraints.Nullable;

public class MyRequest {
    @Nullable
    private Integer myField;
    // getters and setters
}

@RestController
public class MyController {

    @PostMapping("/my-endpoint")
    public ResponseEntity<?> handleRequest(@Valid @RequestBody MyRequest request) {
        // handle request
        return ResponseEntity.ok().build();
    }
}