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javacachingdata-structurescollections

Object cache data structure with "object expiration"

Which data structure in Java would be best to implement an in-memory object cache, where objects have an individual expiration time?

Basically for the cache I could use a Map (where key could be a String) which offers the put and get methods, and use a ordered list of "timestamp"+"object" pairs to manage the expiration time. So a cleanup thread could check the first list entry and delete the object when its expiration time passed. (Deletion of the first element should be in O(1) time)

Solution

  • What you're describing building is basically my ExpiringMap. There are other similar implementations, such as Guava (see CacheBuilder) - though I don't believe it supports per-entry expiration as ExpiringMap does.