Package com.google.common.collect

Class ForwardingIterator<T>

  • All Implemented Interfaces:
    <T>
    Direct Known Subclasses:
    ForwardingListIterator
    @GwtCompatible
public abstract class ForwardingIterator<T>
extends ForwardingObject
implements <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 .

    default method warning: This class forwards calls to only some default methods. Specifically, it forwards calls only for methods that existed . 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 Summary

      Constructors 
      Modifier Constructor Description
      protected ForwardingIterator()
      Constructor for use by subclasses.

    • Method Summary

      All Methods Instance Methods Abstract Methods Concrete Methods 
      Modifier and Type Method Description
      protected abstract <T> delegate()
      Returns the backing delegate instance that methods are forwarded to.
      boolean hasNext()
      Returns true if the iteration has more elements.
      T next()
      Returns the next element in the iteration.
      void remove()
      Removes from the underlying collection the last element returned by this iterator (optional operation).

      • Methods inherited from class java.lang.

        , , , , , , , , ,

      • Methods inherited from interface java.util.

    • Constructor Detail

    • Method Detail

      • delegate

        protected abstract <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: 
        Returns true if the iteration has more elements. (In other words, returns true if would return an element rather than throwing an exception.)
        Specified by:
         in interface <T>
        Returns:
        true if the iteration has more elements

      • next

        public T next()
        Description copied from interface: 
        Returns the next element in the iteration.
        Specified by:
         in interface <T>
        Returns:
        the next element in the iteration

      • remove

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

        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 method.

        Specified by:
         in interface <T>