ChoiceFormat can be created with incomplete limits and formats via applyPattern() or setChoices(). Calling format() with those objects throws an AIOOBE

For example, (the constructors invoke the mentioned setter methods)

new ChoiceFormat("").format(1); // throws AIOOBE
new ChoiceFormat(new double[]{}, new String[]{}).format(1); // throws AIOOBE

It would be great if the setter methods could have made input checks, but for compatibility reasons this cannot be done. At a minimum, the undocumented AIOOBE should be clarified.