使用spring mvc的scala中的JSR303 ConstraintValidator

Question

我已经混合了斯卡拉-Java spring-引导mvc项目。我试图使用javax.validation.constraintvalidator
实现请求bean的自定义验证器，我从这里和其他线程中了解到，用Java编写注释更好，scala支持JSR-303验证吗？

我用Java编写了自定义约束注释，用scala编写了ConstraintValidator类，但当我指定@Constraint(validatedBy=ScalacustomerValidator.class)时，它给出了类型不匹配的编译错误：无法从类 转换为类<？extends ConstraintValidator<？,？>>[] 。我的ScalaCustomerValidator确实扩展了ConstraintValidator。

//Java

@Constraint(validatedBy = ScalaCustomerValidator.class) //Type mismatch error 
@Target(value = ElementType.TYPE)
@Retention(RetentionPolicy.RUNTIME)
public @interface ScalaCustomerValid {
    String message() default "Invalid tab to filter combination";
    Class<?>[] groups() default {};
    Class<? extends Payload>[] payload() default {};
}

//ConstraintValidator的Scala定义

class ScalaCustomerValidator extends ConstraintValidator[ScalaCustomerValid, ScalaCustomer] { .. }

javap输出：

javap ScalaCustomerValidator
Warning: Binary file ScalaCustomerValidator contains com.ScalaCustomerValidator
Compiled from "ScalaCustomerValidator.scala"
public class com.ScalaCustomerValidator implements javax.validation.ConstraintValidator<com.ScalaCustomerValid, com.ScalaCustomer> {
  public void initialize(com.ScalaCustomerValid);
  public boolean isValid(com.ScalaCustomer, javax.validation.ConstraintValidatorContext);
  public boolean isValid(java.lang.Object, javax.validation.ConstraintValidatorContext);
  public void initialize(java.lang.annotation.Annotation);
  public com.ScalaCustomerValidator();
}

Answer 1

您的问题是由于无法获得scala对象的类造成的。Scala编译器为对象ScalaCustomerValidator生成名为ScalaCustomerValidator$的类。ScalaCustomerValidator$实际上实现了ConstraintValidator，没有办法引用它的类。如果您在Scala中尝试：

val cl = classOf[ScalaCustomerValidator]

您也会得到编译错误。

此问题仍未解决:https://issues.scala-lang.org/I#browse/SI-2453