Retrieving expired objects in Ehcache

Question

I'd like to implement the following algorythm above Ehcache :

• try to get an element from the cache
• if the element is not expired
  • serve the value
• else
  • serve the expired value
  • refresh the element in the background

But I never get an expired element (Element.isExpired()). I tried to play with my cache configuration (especially TimeToLive and TimeToIdle) but I cant seem to get it to work as I want. I can list the keys in the cache, but if I "get()" an expired element, I always get a null.

What am I doing wrong ?

Answer 1

You're not doing anything wrong. The documentation says that getting an expired element will remove it from the cache and return null.

I suspect the only time an element will come up as expired is if you have an event listener listenings for element expiry events but I can't say I've ever tested this.