I’m calling a method in another API that accepts a java.util.Collection of objects. I’ve looked at the method and it immediately copies everything in the collection into a new ArrayList before performing its task.
This got me wondering: What is the absolute lowest overhead Java Collection that I can use to quickly assemble parameters for this method?
Answer
That depends on how it copies the elements, but if it creates the ArrayList-copy like this
new ArrayList<Something>(inputCollection);
or if it does
someCopy.addAll(inputCollection);
then the it will go through the inputCollection.toArray() which is probably best implemented by ArrayList.