Oct 4, 2012 · 23 Personally, I prefer to use empty collections instead of null and have the algorithms work in a way that for the algorithm it does not matter if the collection is empty or not.

May 12, 2014 · As we all know with Java comes the Collections API that provide us with numerous data structures that we can use. I was wondering if there is some …

The other advantage of using Apache commons-collections CollectionUtils.isEmpty (or CollectionUtils.isNotEmpty) is that your if condition has less branches, so it is easier to reach a …

Usually an instance of java.util.Collection (although java.util.Map is officially also a part of the collections framework) Although the Collection interface can be implemented directly, usually …

Jul 23, 2010 · 3 Collection is the main interface of Java Collections hierarchy and List (Sequence) is one of the sub interfaces that defines an ordered collection.

Collections.sort(list, comparator); If you are using Java 7 or below then you can use a comparator for customized sorting order by implementing compare method. For example:

229 Assuming that you are using Java 1.5, and that you cannot add Google Collections, I would do something very similar to what the Google guys did. This is a slight variation on Jon's …

Oct 5, 2009 · Java collections Arrays.asList takes var-arg of type T (T ...). If you pass a primitive array (int array), asList method will infer and generate a List<int[]>, which is a one element list …

12 Remember that, converting from List to Set will remove duplicates from collection because List supports duplicates but Set does not support duplicates in Java. Direct Conversion : The most …

Apr 27, 2013 · 12 Collections.sort allows you to pass an instance of a Comparator which defines the sorting logic. So instead of sorting the list in natural order and then reversing it, one can …