调整泛型抛出迭代器的异常类型

我有一个界面 ThrowingIterator ,遵循通用合同 Iterator ,除了 hasNext() 和 next() 方法可以抛出异常:

public interface ThrowingIterator<T, E extends Throwable> {
  boolean hasNext() throws E;
  T next() throws E;
  default void remove() throws E { /* throw unsupported */ }
  // forEachRemaining same as Iterator
}

我可以使用adapt函数更改迭代器的返回类型,类似于 Stream 有 map(Function<? super T, U> mapper) 然而,我还没有找到一种方法来更改迭代器的异常类型,如下所示:

// example method
default <X extends Throwable> ThrowingIterator<T, X> adaptException(Function<? super E, ? extends X> exceptionMapper) {
  return new ThrowingIterator<T, X> {
    public boolean hasNext() {
      try {
        return this.hasNext();
      } catch (E e) { // this does not work, can't catch E
        throw exceptionMapper.apply(e);
      }
    }
  }
  // same for next()
}

// example use
ThrowingIterator<Integer, IOException> baseIterator = getIterator();
ThrowingIterator<Integer, ExecutionException> adaptedIterator = baseIterator.adaptException(ExecutionException::new);

编写此函数的主要困难在于Java不允许捕获泛型异常类型。有没有办法绕过这个限制?我能抓住一切 Throwable s,并使用类对象检查它们是否是预期的类型,但这感觉很笨拙。