java - 约束验证

Question

我正在使用javax.validation.Validator相关类进行基于注释的验证。

Configuration<?> configuration = Validation.byDefaultProvider().configure();   
ValidatorFactory factory = configuration.buildValidatorFactory();   
Validator validator = factory.getValidator(); 

Set<ConstraintViolation<ValidatableObject>> constraintViolations = validator.validate(o);   
for (ConstraintViolation<ValidatableObject> value : constraintViolations) {   
     List< Class< ? extends ConstraintValidator< ? extends Annotation,?>>> list = 
             value.getConstraintDescriptor().getConstraintValidatorClasses();  
}

我收到一个编译错误，说明：

类型不匹配：无法从 List< Class< 转换？将 ConstraintValidator< capture#4-of ?,?>>> 扩展到 List< Class< ? 扩展 ConstraintValidator< ? 扩展注释，？>>>

我错过了什么？

Answer 1

如果您不介意使用ConstraintValidator<?, ?>（即您不需要ConstraintValidator<? extends Annotation, ?>），这应该可以：

Configuration<?> configuration = Validation.byDefaultProvider().configure();   
ValidatorFactory factory = configuration.buildValidatorFactory();   
Validator validator = factory.getValidator(); 

Set<ConstraintViolation<ValidatableObject>> constraintViolations = validator.validate(o);   
for (ConstraintViolation<ValidatableObject> value : constraintViolations) {   
     List< Class< ? extends ConstraintValidator<?,?>>> list = 
             value.getConstraintDescriptor().getConstraintValidatorClasses();  
}