Singleton pattern backfired on me
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This is a continuation of my earlier post of Tree, recursive function and my dumb mistake. As I said in my last post, my solution was to create hash maps (singleton) to store those for the session. The main motivation was to help out the performance. But I found out it backfired on me, a few days ago and today. In both cases, it has to do with the hash map I created, it was something like
(object , a list of objects). In both cases the list of objects was actually dynamic, and I made an assumption it was static. In other words, I thought I only need to put the mapping to the map once, then I can use it happily ever after. I think there might be ways to get around it, i.e., I should update the map when that list does change. I will investigate and work on it more. (Update 05-30-14) So I found a solution to one scenario, I was able to update the map as needed. And I use put method (java hashmap) to do that update.