是否存在一种更优雅的方法来将元素从一个集合中抽取到另一个集合中？

Question

Based on a condition, certain elements should be drained from one collection to the other. To avoid concurrent modification, my current approach is (pseudo code):

Set<Integer> drained
for (i in sourceCollection index)
    if (condition met)
        drained.add(i)
        destinationCollection.add(element)

Collection<Object> remaining
for (i in sourceCollection index)
    if (i not in drained)
        remaining.add(element)

sourceCollection = remaining

Is there a shorter/elegant approach?

Answer 1

You can use an iterator for this:

for (Iterator<String> iterator = source.iterator(); iterator.hasNext(); ) {
    String element = iterator.next();
    if (shouldDrain(element)) {
        destination.add(element);
        iterator.remove();
    }
}