Best practice to validate null and empty collection in Java
4 DFómh 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.
Java Collections: which collection to use and when?
12 Beal 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 …
What is a java collection? - Stack Overflow
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 …
What is the difference between Collection and List in Java?
23 Iúil 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.
Checking if a collection is empty in Java: which is the best method?
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 …
java - What is the Simplest Way to Reverse an ArrayList ... - Stack ...
26 Beal 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 …
How to use Comparator in Java to sort - Stack Overflow
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:
java - Random shuffling of an array - Stack Overflow
5 DFómh 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 …
How to filter a Java Collection (based on predicate)?
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 …
How to sort List of objects by some property - Stack Overflow
1 In java you need to use the static Collections.sort method. Here is an example for a list of CompanyRole objects, sorted first by begin and then by end. You can easily adapt for your own …