javax.validation 请求参数校验小问题: @Min 不校验是否为空

想用@Min 来校验是否为空,  结果发现不行,  看来是必须用到 @NotNull  注解了. 如下. 

我的代码是:

@Min(value = 0,message = MsgCdConstant.AMOUNT_MUST_BE_POSITIVE)

http请求报错:

HV000030: No validator could be found for constraint 'javax.validation.constraints.NotEmpty' validating type 'java.lang.Integer'. Check configuration for 'body.amount'

详细如下:

javax.validation.UnexpectedTypeException: HV000030: No validator could be found for constraint 'javax.validation.constraints.NotBlank' validating type 'java.lang.Integer'. Check configuration for 'body.amount'
    at org.hibernate.validator.internal.engine.constraintvalidation.ConstraintTree.getExceptionForNullValidator(ConstraintTree.java:108)
    at org.hibernate.validator.internal.engine.constraintvalidation.ConstraintTree.getInitializedConstraintValidator(ConstraintTree.java:140)
    at org.hibernate.validator.internal.engine.constraintvalidation.SimpleConstraintTree.validateConstraints(SimpleConstraintTree.java:55)
    at org.hibernate.validator.internal.engine.constraintvalidation.ConstraintTree.validateConstraints(ConstraintTree.java:73)
    at org.hibernate.validator.internal.metadata.core.MetaConstraint.doValidateConstraint(MetaConstraint.java:127)
    at org.hibernate.validator.internal.metadata.core.MetaConstraint.validateConstraint(MetaConstraint.java:120)
    at org.hibernate.validator.internal.engine.ValidatorImpl.validateMetaConstraint(ValidatorImpl.java:552)
    at org.hibernate.validator.internal.engine.ValidatorImpl.validateConstraintsForSingleDefaultGroupElement(ValidatorImpl.java:515)
    at org.hibernate.validator.internal.engine.ValidatorImpl.validateConstraintsForDefaultGroup(ValidatorImpl.java:485)
    at org.hibernate.validator.internal.engine.ValidatorImpl.validateConstraintsForCurrentGroup(ValidatorImpl.java:447)
    at org.hibernate.validator.internal.engine.ValidatorImpl.validateInContext(ValidatorImpl.java:397)
    at org.hibernate.validator.internal.engine.ValidatorImpl.validateCascadedAnnotatedObjectForCurrentGroup(ValidatorImpl.java:624)
    at org.hibernate.validator.internal.engine.ValidatorImpl.validateCascadedConstraints(ValidatorImpl.java:587)
    at org.hibernate.validator.internal.engine.ValidatorImpl.validateInContext(ValidatorImpl.java:406)
    at org.hibernate.validator.internal.engine.ValidatorImpl.validate(ValidatorImpl.java:173)
    at org.springframework.validation.beanvalidation.SpringValidatorAdapter.validate(SpringValidatorAdapter.java:104)
    at org.springframework.boot.autoconfigure.validation.ValidatorAdapter.validate(ValidatorAdapter.java:64)
    at org.springframework.validation.DataBinder.validate(DataBinder.java:874)
    at org.springframework.web.servlet.mvc.method.annotation.AbstractMessageConverterMethodArgumentResolver.validateIfApplicable(AbstractMessageConverterMethodArgumentResolver.java:260)
    at org.springframework.web.servlet.mvc.method.annotation.RequestResponseBodyMethodProcessor.resolveArgument(RequestResponseBodyMethodProcessor.java:136)
    at org.springframework.web.method.support.HandlerMethodArgumentResolverComposite.resolveArgument(HandlerMethodArgumentResolverComposite.java:124)

坑爹啊,  必须十分小心才行, 其实原因很简单, 就是用法不对.  类似的还有 @ Max  @Positive , 只在变量有值的时候进行校验,  变量为空或不存在的时候, 其实不会起作用.

简单来说, 如果需要判断某参数不能为空且必须是正数, 那么需要使用两个注解: @NotNull  @Min 配合使用才行!!