I've always been a big fan of Java, especially since its promise "Write once, run everywhere" comes very close - at least if you compare the situation with the C/C++ world 8 years ago (and take all the libraries into account).

However, this promise nearly killed my Christmas last year. Ever used the new fancy ScheduledThreadPoolExecutor? Nice class. Easy task handling in a multi-threaded application design (at least if you dont try to extend it, but this is another story). I've developed my application on Windows, we did extensive tests in a Linux environment and when we delivered the application to our customer's location Friday before Christmas it crashed quite instantly. Within the logger! What's that?

How often do you imply facts that nowhere have been stated or confirmed? Last week I found myself trapped by such a certainty that revealed to be a false assumption.

Ever asked yourself what you can expect from the values delievered by the JDK's method System.identityHashCode(Object object) ? My original believe (and I suppose I am not alone here) was that the value reflects somehow the memory address of the given object. Not that I tried to access the object in any obscure way, it was just based on the fact that there are not a lot of more things to assign an identity to an object - implying that identity has something to do with uniqueness for the object's lifetime.