@Valid 參數校驗不生效問題解決

問題現象

import lombok.Data;

import javax.validation.constraints.NotNull;

@Data
public class IDDTO {

    @NotNull
    private Long id;
}

@Slf4j
@Controller
@RequestMapping("/example")
public class ExampleController {

    @POSTMapping(value = "/valid")
    public BaseResponseVO valid(@Valid IDDTO idDTO, BindingResult bindingResult){
        if(bindingResult.hasErrors()){
            log.error("what fuck");
        }
        return BaseResponseVO.success();
    }

}

看起來像不像會打印what fuck，實際上居然不會。實際上是因爲Valid Property 會在json序列化構建Java Bean的時候，所以這裏的Post請求還必須是application/json 即：

    @POSTMapping(value = "/valid")
    public BaseResponseVO valid(@Valid @RequestBody IDDTO idDTO, BindingResult bindingResult){
        if(bindingResult.hasErrors()){
            log.error("what fuck");
        }
        return BaseResponseVO.success();
    }

手動檢查

如果有其他情況發現@Valid不生效，提供一個手動檢查的方案

import org.apache.commons.collections.CollectionUtils;

import javax.validation.ConstraintViolation;
import javax.validation.Validation;
import javax.validation.Validator;
import java.util.HashMap;
import java.util.Map;
import java.util.Set;

public class ValidateUtil {
    private static Validator validator = Validation.buildDefaultValidatorFactory()
            .getValidator();

    public static void beanValidate(Object obj) {
        Map<String, String> validatedMsg = new HashMap<>();
        Set<ConstraintViolation<Object>> constraintViolations = validator.validate(obj);
        for (ConstraintViolation<Object> c : constraintViolations) {
            validatedMsg.put(c.getPropertyPath().toString(), c.getMessage());
        }
        if (CollectionUtils.isNotEmpty(constraintViolations)) {
            throw new Exception(validatedMsg);
        }

    }

}

即：

@Slf4j
@Controller
@RequestMapping("/example")
public class ExampleController {

    @POSTMapping(value = "/valid")
    public BaseResponseVO valid(IDDTO idDTO){
        ValidateUtil.beanValidate(idDTO);
        return BaseResponseVO.success();
    }

}