Package com.google.common.collect

Class ForwardingIterator<T>

  • All Implemented Interfaces:
    Iterator<T>
    Direct Known Subclasses:
    ForwardingListIterator
    @GwtCompatible
public abstract class ForwardingIterator<T>
extends ForwardingObject
implements Iterator<T>
    An iterator which forwards all its method calls to another iterator. Subclasses should override one or more methods to modify the behavior of the backing iterator as desired per the decorator pattern.

    default method warning: This class forwards calls to only some default methods. Specifically, it forwards calls only for methods that existed before default methods were introduced. For newer methods, like forEachRemaining, it inherits their default implementations. When those implementations invoke methods, they invoke methods on the ForwardingIterator.

    Since:
    2.0
    Author:
    Kevin Bourrillion

    • Constructor Detail

    • Method Detail

      • delegate

        protected abstract Iterator<T> delegate()
        Description copied from class: ForwardingObject
        Returns the backing delegate instance that methods are forwarded to. Abstract subclasses generally override this method with an abstract method that has a more specific return type, such as ForwardingSet.delegate(). Concrete subclasses override this method to supply the instance being decorated.
        Specified by:
        delegate in class ForwardingObject

      • hasNext

        public boolean hasNext()
        Description copied from interface: java.util.Iterator
        Returns true if the iteration has more elements. (In other words, returns true if Iterator.next() would return an element rather than throwing an exception.)
        Specified by:
        hasNext in interface Iterator<T>
        Returns:
        true if the iteration has more elements

      • remove

        public void remove()
        Description copied from interface: java.util.Iterator
        Removes from the underlying collection the last element returned by this iterator (optional operation). This method can be called only once per call to Iterator.next().

        The behavior of an iterator is unspecified if the underlying collection is modified while the iteration is in progress in any way other than by calling this method, unless an overriding class has specified a concurrent modification policy.

        The behavior of an iterator is unspecified if this method is called after a call to the forEachRemaining method.

        Specified by:
        remove in interface Iterator<T>