Comments on: Remove duplicates http://blog.refactor.se/2006/07/31/remove-duplicates/ Thoughts on Java, Agile, OS X and life in general.. Fri, 09 Apr 2010 08:35:07 +0000 http://wordpress.org/?v=2.9.2 hourly 1 By: Stephen Colebourne http://blog.refactor.se/2006/07/31/remove-duplicates/comment-page-1/#comment-23 Stephen Colebourne Tue, 01 Aug 2006 02:05:26 +0000 http://blog.refactor.se/2006/07/31/remove-duplicates/#comment-23 Just be aware that this method does create a lot of objects behind the scenes. A LinkedHashSet uses a LinkedHashMap, which creates one entry (object) for every item added. Clearly these all need to be created and garbage collected. Depending on your setup that may be important. (Normally though, I would advise not worrying too much about object creation and gc ;-) But for a smaller list it may be quicker to deduplicate without the Set. Just be aware that this method does create a lot of objects behind the scenes. A LinkedHashSet uses a LinkedHashMap, which creates one entry (object) for every item added. Clearly these all need to be created and garbage collected. Depending on your setup that may be important. (Normally though, I would advise not worrying too much about object creation and gc ;-) But for a smaller list it may be quicker to deduplicate without the Set.

]]> By: Brian http://blog.refactor.se/2006/07/31/remove-duplicates/comment-page-1/#comment-22 Brian Mon, 31 Jul 2006 22:51:32 +0000 http://blog.refactor.se/2006/07/31/remove-duplicates/#comment-22 You might be better off with the following.... public void removeDuplicates(List items) { Set set = new LinkedHashSet(); set.addAll(items); items.removeAll(); items.addAll(set); } This way you'll still have the same object reference that you started with instead of a completely new list. You might be better off with the following….

public void removeDuplicates(List items) {
Set set = new LinkedHashSet();
set.addAll(items);
items.removeAll();
items.addAll(set);
}

This way you’ll still have the same object reference that you started with instead of a completely new list.

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