Note that this occurs because of the autoboxing of 4 needed to pass it to the Object[] used in printf(). Sticking to primitives, you're unaffected. <br><br>Also, this seems to be blocked in newer JDKs, ("An illegal reflective access operation has occurred") until I added the option --illegal-access=warn<br><br>Edit: nvm, it wasn't blocked, just a very verbose warning that was made smaller by that option.