Exceptions in Iterator.forEachRemaining()

[Martin Buchholz]

Mostly my fault, and even more inconsistent than you say.  I filed
https://bugs.openjdk.java.net/browse/JDK-8213038
(but don't use an iterator after a call to forEachRemaining!)

On Thu, Oct 25, 2018 at 11:55 PM, Zheka Kozlov <orionllmain at gmail.com>
wrote:

> Hi everyone.
>
> I noticed that different Iterator implementations behave differently when
> an Exception is thrown inside a Consumer passed to forEachRemaining():
>
> private static void test(List<Integer> list) {
>     Iterator<Integer> iterator = list.iterator();
>     try {
>         iterator.forEachRemaining(i -> {
>             if (i == 3) {
>                 throw new RuntimeException();
>             } else {
>                 System.out.print(i);
>             }
>         });
>     } catch (RuntimeException ex) {
>     }
>     iterator.forEachRemaining(System.out::print);
> }
>
> public static void main(String... args) throws Throwable {
>     test(List.of(1, 2, 3, 4, 5)); // Prints 1245
>     System.out.println();
>     test(Arrays.asList(1, 2, 3, 4, 5)); // Prints 1245
>     System.out.println();
>     test(new LinkedList<>(List.of(1, 2, 3, 4, 5))); // Prints 12345 (BAD)
>     System.out.println();
>     test(new ArrayList<>(List.of(1, 2, 3, 4, 5))); // Prints 1212345 (BAD)
> }
>
> Is this a bug? I think yes because an overridden forEachRemaining() should
> behave the same as the default implementation:
>
> while (hasNext()) {
>     action.accept(next());
> }
>
> So, in this case, List.of() and Arrays.asList() are correct while
> LinkedList and ArrayList are not.
>