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 collection/tutorial/advice that could …

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.

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 comments. …

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 good …

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 client code will use …

Collections.emptyList() does not need to create a new object for each call; it's typical, as in OpenJDK, to just return the singleton EMPTY_LIST object. Additionally, it's clearer that you intend to mean an …

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 (the one …

May 26, 2012 · final List<T> result = new ArrayList<>(list); Collections.reverse(result); return result; } This approach works, but requires iterating over the list twice. The copy constructor (new …

Today I was happily coding away when I got to a piece of code I already used hundreds of times: Iterating through a Collection (here ArrayList) For some reason, I actually looked at the autocompl...

Jul 6, 2017 · Collections.sort(tasks, comparadorFecha); //ok showTask(); } Ahora sí, comparadorFecha, y comparadorPrioridad deben ser instancias de alguna clase que implemente la interfaz …