Can I iterate through a NodeList using for-each in Java?

Question

I want to iterate through a NodeList using a for-each loop in Java. I have it working with a for loop and a do-while loop but not for-each.

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Answer 1

If the current DOM element is removed (via JavaScript) while iterating a NodeList (created from getElementsByTagName() and maybe others), the element will disappear from the NodeList. This makes correct iteration of the NodeList more tricky.

public class IteratableNodeList implements Iterable {
    final NodeList nodeList;
    public IteratableNodeList(final NodeList _nodeList) {
        nodeList = _nodeList;
    }
    @Override
    public Iterator iterator() {
        return new Iterator() {
            private int index = -1;
            private Node lastNode = null;
            private boolean isCurrentReplaced() {
                return lastNode != null && index < nodeList.getLength() &&
                       lastNode != nodeList.item(index);
            }

            @Override
            public boolean hasNext() {
                return index + 1 < nodeList.getLength() || isCurrentReplaced();
            }

            @Override
            public Node next() {
                if (hasNext()) {
                    if (isCurrentReplaced()) {
                        //  It got removed by a change in the DOM.
                        lastNode = nodeList.item(index);
                    } else {
                        lastNode = nodeList.item(++index);
                    }
                    return lastNode;
                } else {
                    throw new NoSuchElementException();
                }
            }

            @Override
            public void remove() {
                throw new UnsupportedOperationException();
            }
        };
    }

    public Stream stream() {
        Spliterator spliterator =
            Spliterators.spliterator(iterator(), nodeList.getLength(), 0);
        return StreamSupport.stream(spliterator, false);
    }
}

Then use it like this: new IteratableNodeList(doc.getElementsByTagName(elementType)). stream().filter(...)

Or: new IteratableNodeList(doc.getElementsByTagName(elementType)).forEach(...)