Use of com.google.appengine.repackaged.* classes in GAE/J

Is there any problem with usin开发者_如何学编程g classes in com.google.appengine.repackaged.* ?

I mean, it it an unofficial API, is it subject to change or could it be a source of future problems ?

They will (should?) work, but I believe the official line is that they aren't guaranteed to stick around in later versions of the SDK. If you find yourself needing a package under repackaged, you should use the library directly, so you have more complete control over your dependencies.