Nicolas Malin created OFBIZ-6298: ------------------------------------ Summary: 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
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 -- This message was sent by Atlassian JIRA (v6.3.4#6332)