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https://issues.apache.org/jira/browse/OFBIZ-6298?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14510624#comment-14510624
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Nicolas Malin edited comment on OFBIZ-6298 at 4/24/15 8:17 AM:
---------------------------------------------------------------
{quote}
[~deepak.dixit] : We should use the LinkedHashMap for controller pre/post
processor eventLists (ConfigXMLReader.java:180) as HashMap does not maintain
the iteration order.
{quote}
was (Author: soledad):
{quote}
[~deepak] : We should use the LinkedHashMap for controller pre/post processor
eventLists (ConfigXMLReader.java:180) as HashMap does not maintain the
iteration order.
{quote}
> Java collection use optimized
> -----------------------------
>
> Key: OFBIZ-6298
> URL: https://issues.apache.org/jira/browse/OFBIZ-6298
> Project: OFBiz
> Issue Type: Improvement
> Components: ALL COMPONENTS
> Affects Versions: Trunk
> Reporter: Nicolas Malin
> Assignee: Nicolas Malin
> Priority: Minor
> Labels: collection, performance
>
> With the javolution collection cleaning (OFBIZ-5169,OFBIZ-5781) , we need to
> realize a second pass to control what instantiation would be better.
> For List between LinkedList, ArrayList
> {quote}
> Using ArrayList, rather than LinkedList, as a default is a good approach
> because ArrayList will work better in most situations (in terms of
> algorithmic runtimes and memory footprints).
> However I think it is important to wisely choose ArrayList or LinkedList
> based on the context, because sometimes a linked list may be a better choice:
> I am not saying we should do it now and we can tackle this at a later moment,
> possibly focusing only on list that can be very big and analyzing their usage
> to see if array or linked list is better; it would be also nice, when we use
> ArrayList, to see if we can predict the capacity of the list and allocate it
> at creation: if we can do this we will have a more predictable memory usage
> and less unpredictable peaks under heavy load (when the array capacity is
> reached and the array is copied to a new one with double capacity).
> {quote}
> more documentation on :
> *
> https://docs.oracle.com/javase/tutorial/collections/implementations/list.html
> *
> http://stackoverflow.com/questions/322715/when-to-use-linkedlist-over-arraylist
> For Map between HashMap and LinkedHashMap :
> {quote}
> Javolution Map Iterators return items in insertion sequence (HashMap does
> not), so any code relying on the original insertion order must use a
> LinkedHashMap.
> {quote}
> *
> http://stackoverflow.com/questions/2889777/difference-between-hashmap-linkedhashmap-and-treemap
> If you detect an optimization, please comments this issues
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