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 …

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.

Eclipse Collections If you're using pairs that contain primitives, Eclipse Collections provides some very efficient primitive pair classes that will avoid all the inefficient auto-boxing and auto …

Nov 4, 2009 · If I have a collection, such as Collection<String> strs, how can I get the first item out? I could just call an Iterator, take its first next(), then throw the Iterator away. Is there …

Nov 8, 2009 · 37 It's not directly possible to reverse sort an array of primitives (i.e., int[] arr = {1, 2, 3};) using Arrays.sort() and Collections.reverseOrder() because those methods require …

Collections.sort(list, comparator); In general, it's a good idea to implement Comparable<T> if there's a single "natural" sort order... otherwise (if you happen to want to sort in a particular …

Unmodifiable collections are usually read-only views (wrappers) of other collections. You can't add to, remove from or clear them, but the underlying collection can change. Immutable …

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 …

Oct 10, 2008 · Avoid Apache Commons Collections. It’s not typesafe, there are no generics. Great if you use Java 1.4, but for Java 5 and above, I’d prefer Google Guava.

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.