Package org.eclipse.persistence.jpa.jpql.tools.utility.iterator

Class CloneIterator<E>

  • Type Parameters:
    E - the type of elements returned by the iterator
    All Implemented Interfaces:
    Iterator<E>
    Direct Known Subclasses:
    SnapshotCloneIterable.LocalCloneIterator
    public class CloneIterator<E>
extends Object
implements Iterator<E>
    A CloneIterator iterates over a copy of a collection, allowing for concurrent access to the original collection.

    The original collection passed to the CloneIterator's constructor should be synchronized (e.g. Vector); otherwise you run the risk of a corrupted collection.

    By default, a CloneIterator does not support the remove() operation; this is because it does not have access to the original collection. But if the CloneIterator is supplied with an CloneIterator.Remover it will delegate the remove() operation to the CloneIterator.Remover. Alternatively, a subclass can override the remove(Object) method.

    See Also:
    LiveCloneIterable, SnapshotCloneIterable

    • Constructor Detail

      • CloneIterator

        public CloneIterator​(Collection<? extends E> collection)
        Construct an iterator on a copy of the specified collection. The remove() method will not be supported, unless a subclass overrides the remove(Object).

      • CloneIterator

        public CloneIterator​(E[] array)
        Construct an iterator on a copy of the specified array. The remove() method will not be supported, unless a subclass overrides the remove(Object).

      • CloneIterator

        public CloneIterator​(Collection<? extends E> collection,
                     CloneIterator.Remover<E> remover)
        Construct an iterator on a copy of the specified collection. Use the specified remover to remove objects from the original collection.

      • CloneIterator

        public CloneIterator​(E[] array,
                     CloneIterator.Remover<E> remover)
        Construct an iterator on a copy of the specified array. Use the specified remover to remove objects from the original array.

      • CloneIterator

        protected CloneIterator​(CloneIterator.Remover<E> remover,
                        Object... array)
        Internal constructor used by subclasses. Swap order of arguments to prevent collision with other constructor. The passed in array will *not* be cloned.

    • Method Detail

      • hasNext

        public boolean hasNext()
        Specified by:
        hasNext in interface Iterator<E>

      • next

        public E next()
        Specified by:
        next in interface Iterator<E>

      • remove

        public void remove()
        Specified by:
        remove in interface Iterator<E>

      • nestedNext

        protected E nestedNext()
        The collection passed in during construction held elements of type E, so this cast is not a problem. We need this cast because all the elements of the original collection were copied into an object array (Object[]).

      • remove

        protected void remove​(E e)
        Remove the specified element from the original collection.

        This method can be overridden by a subclass as an alternative to building a CloneIterator.Remover.