Module java.desktop

Class ElementIterator

  • All Implemented Interfaces:
    Cloneable

    public class ElementIterator
    extends Object
    implements Cloneable

    ElementIterator, as the name suggests, iterates over the Element tree. The constructor can be invoked with either Document or an Element as an argument. If the constructor is invoked with a Document as an argument then the root of the iteration is the return value of document.getDefaultRootElement(). The iteration happens in a depth-first manner. In terms of how boundary conditions are handled: a) if next() is called before first() or current(), the root will be returned. b) next() returns null to indicate the end of the list. c) previous() returns null when the current element is the root or next() has returned null. The ElementIterator does no locking of the Element tree. This means that it does not track any changes. It is the responsibility of the user of this class, to ensure that no changes happen during element iteration. Simple usage example: public void iterate() { ElementIterator it = new ElementIterator(root); Element elem; while (true) { if ((elem = next()) != null) { // process element System.out.println("elem: " + elem.getName()); } else { break; } } }

    • Constructor Detail

      • ElementIterator

        public ElementIterator​(Document document)
        Creates a new ElementIterator. The root element is taken to get the default root element of the document.
        Parameters:
        document - a Document.
      • ElementIterator

        public ElementIterator​(Element root)
        Creates a new ElementIterator.
        Parameters:
        root - the root Element.
    • Method Detail

      • clone

        public Object clone()
        Clones the ElementIterator.
        Overrides:
        clone in class Object
        Returns:
        a cloned ElementIterator Object.
        See Also:
        Cloneable
      • first

        public Element first()
        Fetches the first element.
        Returns:
        an Element.
      • depth

        public int depth()
        Fetches the current depth of element tree.
        Returns:
        the depth.
      • current

        public Element current()
        Fetches the current Element.
        Returns:
        element on top of the stack or null if the root element is null
      • next

        public Element next()
        Fetches the next Element. The strategy used to locate the next element is a depth-first search.
        Returns:
        the next element or null at the end of the list.
      • previous

        public Element previous()
        Fetches the previous Element. If however the current element is the last element, or the current element is null, then null is returned.
        Returns:
        previous Element if available