Ola Bini :

When looking at GAE/J, it’s important to keep in mind the security restrictions that Google has been forced to implement, to make the Java implementation totally safe for them. This includes restrictions of many kinds, and some of them might come as a bit of a surprise in some cases. One of the larger things you will notice is that some classes aren’t available - and you will get a ClassNotFoundException if you try to use them from your application. Personally, I believe that using a SecurityException when trying to load these might have been better, but this fact remains: many classes you expect will not be there.

Article très intéressant, je vous en recommande la lecture.

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