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javacollectionsoverhead

java.util.Collection with the lowest overhead?

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?

Solution

  • 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.