Does Java support RAII/deterministic destruction?

Question

It\'s been at least 5 years since I worked with Java, and back then, any time you wanted to allocate an object that needed cleaning up (e.g. sockets, DB handles), you had to

Answer 1

There is a pattern that helps here. It's not as nice as destructor based RAII but it does mean that the resource clean-up can be moved to the library (so you can't forget to call it).

It's called Execute Around, and has been discussed here before.

Interestingly I see Jon Skeet chimed in on that thread, but he didn't mention it here - shame on you Jon - missed an opportunity for some rep points there!

BTW, while I'm glad Brian Harry (see Jon's comment, again) went to the lengths of writing the email that he did - and it obviously did reflect a lot of thought that went into the process - and I'm glad we did get "using" out of it in C# - I don't agree with all his conclusions. In particular, I don't see why, if we can have using, we can't have a way to mark a type as behaving that way without "using". Of course it constrains the usage - but so does "using" - and most of the time it's exactly what you want. The trouble with "using" is that the client code still has to remember to use it. With C++ style RAII it's a property of the type. An arguably bigger problem with "using", or more accurately with the Dispose idiom, is that it's a lot more complicated and error prone than most people realise to get right - mostly because of the potential for objects to be brought back from the dead.