@Valid 参数校验不生效问题解决

@Valid 参数校验不生效问题解决

• 问题现象
• 手动检查
• 不生效原因

问题现象

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();
    }

}

看起来像不像会打印what fuck，实际上居然不会。实际上是因为Valid Property 会在json序列化构建Java Bean的时候，所以这里的Post请求还必须是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();
    }

手动检查

如果有其他情况发现@Valid不生效，提供一个手动检查的方案

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();
    }

}

不生效原因

笔者在开发过程中发现有如下一段日志，应该可以定位为什么@Valid不生效，笔者暂时比较忙，稍后再补充分析。如果有同学有兴趣，可以先自行分析。

2020-07-11 11:44:20,468 [main] DEBUG (OptionalValidatorFactoryBean:43) - Failed to set up a Bean Validation provider
: Unable to create a Configuration, because no Bean Validation provider could be found. Add a provider like Hibernate Validator (RI) to your classpath.
	at $(:271) ~[validation-api-1.1.:?]
	at (:255) ~[spring-context-4.3.:4.3.]
	at (:40) [spring-context-4.3.:4.3.]
	at (:1692) [spring-beans-4.3.:4.3.]
	at (:1630) [spring-beans-4.3.:4.3.]
	at (:555) [spring-beans-4.3.:4.3.]
	at (:483) [spring-beans-4.3.:4.3.]
	at $(:312) [spring-beans-4.3.:4.3.]
	at (:230) [spring-beans-4.3.:4.3.]
	at (:308) [spring-beans-4.3.:4.3.]
	at (:197) [spring-beans-4.3.:4.3.]
	at (:761) [spring-beans-4.3.:4.3.]
	at (:867) [spring-context-4.3.:4.3.]
	at (:543) [spring-context-4.3.:4.3.]
	at (:668) [spring-webmvc-4.3.:4.3.]
	at (:634) [spring-webmvc-4.3.:4.3.]
	at (:682) [spring-webmvc-4.3.:4.3.]
	at (:553) [spring-webmvc-4.3.:4.3.]
	at (:494) [spring-webmvc-4.3.:4.3.]
	at (:171) [spring-webmvc-4.3.:4.3.]
	at (:244) [-3.0.0.:?]