If you are working with Eclipse on a Java project, make sure to try a regular (ant) build from time to time. The eclipse compiler sometimes differs quite a lot in what it accepts (especially when it comes to generics it seems to be a bit more clever) or considers a warning.

No, I did not just disable a warning. Eclipse did report some “serialVersionUID” warnings, but it missed lots of them, too. I have the vague impression that the Eclipse java compiler didn’t recognize that a class implementing the “Externalizable” interface also should have a serial version UID.

And unfortunately I didn’t find a way to reach the serial UID generation quickfix without having an eclipse warning… Well, after all there is not much wrong with starting the serial version at 1L.