You can drop Apple Lossless files onto a MicroSD card and the J3 will acknowledge the files (using folder view) but when you attempt to play an Apple Lossless music file it'll just say 'Invalid File'. I know this because I tested my J3 earlier today.
I know of no hack to overcome this, but considering the fact that the J3 will apparently play APE or FLAC files, I don't see it as a problem to convert the Apple Lossless to FLAC or APE.