java.util.Prefs throwing BackingStoreException - Why?

Question

I have a system that caches the tiny/simple results of an on-startup SOAP call

I need instances to be able to reload their cache on startup (in case the SOAP service is

Answer 1

Instead of using Preferences, just use any serializable Map and make a very simple cache class which serializes and deserializes it to a randomly-generated temporary filename (the filename being generated on first initialisation). Since it is only a cache, you can just catch any exceptions and reset the cache back to its initial state when an exception happens, so it will re-fetch from the original data source (the SOAP service in your case). So there's no need to worry about serialVersionUID or any of that compatibility stuff, if you don't want to.