Silly Java rules?

Kevin Barnes observes that some pretty silly rules have developed around the use of Java.

I should declare my interest at this point: I work on Java standards and IBM's Java runtimes. That said, I think some rules of thumb are useful for beginners provided that skilled programmers break the rules as necessary.

I dislike classes with numerous getter and setter methods as this is a pretty strong hint that a class is badly designed, or that the programmer would have preferred a C struct ;-). Some consider these methods inherently evil, but I wouldn't go that far.

The use of final is more interesting. In C++, const is useful in defining good interfaces and final may play a similar role in Java. But the use of final on local declarations doesn't seem to be worth the syntactic clutter.

One of the proponents (thanks for the link, Kevin) of the use of final seems more concerned about controlling subclassing. That's a more interesting point to argue as it comes back to good interface design. But I don't think there's a general rule - it depends on the circumstances. Anyone designing a Java interface needs to understand the trade-off.

Since Java enshrines 'non-final' as the default (and it's too late to change that!), beginners risk coding Java interfaces that will behave unexpectedly when subclassed. But changing the language default wouldn't enable beginners to design good interfaces. As they say "there's no substitute for understanding".