Java EE 参数约束配置奇怪的行为

Question

我试图在标准 AbstractFacade(由 NetBeans 生成)的创建和编辑方法上添加参数约束配置(bean 验证)。

所以我试过:

@Override
public void create(@WkTeilnahmePlanedResult  WkTeilnahme entity) {
   super.create(entity);
}

这返回了消息

A method overriding another method must not alter the parameter constraint configuration when deploying it to Glassfish 4

所以下一次尝试是

  @Override
  public void create(WkTeilnahme entity) {
    checkedCreate(entity);
  }


  private void checkedCreate(@WkTeilnahmePlanedResult WkTeilnahme entity) {
    super.create(entity);
  }

部署没有任何问题......但从未调用 validator 。

你能告诉我为什么吗？

顺便提一句:

  @Override
  public void create(WkTeilnahme entity) {
    throw new UnsupportedOperationException(
            "Create not supported! Use checkedCreate() instead!");
  }


  public void checkedCreate(@WkTeilnahmePlanedResult WkTeilnahme entity) {
    super.create(entity);
  }

这有效，但不是很酷!

Answer 1

关于您的第一次尝试，它不起作用，因为 Bean 验证约束必须遵循 Liskov Substitution Principle .另请参阅相关的 Bean 验证规范部分 - http://beanvalidation.org/1.1/spec/#constraintdeclarationvalidationprocess-methodlevelconstraints-inheritance

从规范:

Very informally speaking, the Liskov substitution principle says that where a given type T is used, it should be possible to replace T with a sub-type S of T ("Behavioral subtyping"). If S overrides/implements a method from T and S would strengthen the method's preconditions (e.g. by adding parameter constraints) this principle would be violated as client code working correctly against T might fail when working against S. Also if S overrides/implements a method from T and S weakens the method's postconditions this principle would be violated. However S may strengthen the method's postconditions (by adding return value constraints), as client code working against T still will work against S.

我认为你的第二个例子应该可以工作，但是，我不熟悉 NetBeans AbstractFacade。我的猜测是调用了 checkedCreate(entity);不通过代理实例，因此不会被拦截。也许您可以发布所涉及类的完整代码？什么类型的类包含这些方法？ session bean？