I am trying to write a class that would trace all Ehcache GET requests. For the performance obsessed - this would only be switched on for debugging purposes.
I can see following three options available:
1) write an implementation of net.sf.ehcache.event.CacheEventListener. This would be my preferred way, but it only has PUT/REMOVE/etc. hooks. No GET. Doh!
2) write an implementation of net.sf.ehcache.statistics.CacheUsageListener. The problem with this approach is that this interface is more designed for statistics and does not even provide access to things like current cache key/element, so I would have to do horrible hacks (think: sharing state through ThreadLocal) to achieve what I want. Yuck!
3) write an Ehcache wrapper, and channel all requests through it. Quite painful as we use Ehcache in different ways (with Hibernate and without), meaning I would have to write different wrappers for all these different cases. Adds maintenance pains and isn't really precise as it is not possible to know, for example, if a GET operation has hit a stale entry or not.
Are there any other options I missed?
A fourth option would be to enable debug level logging for net.sf.ehcache.Cache and enable cache statistics for the caches you want to trace the information. You'd then get "Cache: " + getName() + " store hit for " + key" or "configuration.getName() + " cache hit, but element expired"" log statements... So for misses as well.