org.apache.commons.collections4.iterators

Class ZippingIterator<E>

  • All Implemented Interfaces:
    Iterator<E> 

    public class ZippingIterator<E>
extends Object
implements Iterator<E>
    Provides an interleaved iteration over the elements contained in a collection of Iterators.

    Given two Iterator instances A and B, the next() method on this iterator will switch between A.next() and B.next() until both iterators are exhausted.

    Since:
    4.1

    • Constructor Summary

      Constructors

      Constructor and Description
      ZippingIterator(Iterator<? extends E>... iterators)
      Constructs a new ZippingIterator that will provide interleaved iteration of the specified iterators.
      ZippingIterator(Iterator<? extends E> a, Iterator<? extends E> b)
      Constructs a new ZippingIterator that will provide interleaved iteration over the two given iterators.
      ZippingIterator(Iterator<? extends E> a, Iterator<? extends E> b, Iterator<? extends E> c)
      Constructs a new ZippingIterator that will provide interleaved iteration over the three given iterators.

    • Constructor Detail

      • ZippingIterator

        public ZippingIterator(Iterator<? extends E> a,
                       Iterator<? extends E> b)
        Constructs a new ZippingIterator that will provide interleaved iteration over the two given iterators.
        Parameters:
        a - the first child iterator
        b - the second child iterator
        Throws:
        NullPointerException - if either iterator is null

      • ZippingIterator

        public ZippingIterator(Iterator<? extends E> a,
                       Iterator<? extends E> b,
                       Iterator<? extends E> c)
        Constructs a new ZippingIterator that will provide interleaved iteration over the three given iterators.
        Parameters:
        a - the first child iterator
        b - the second child iterator
        c - the third child iterator
        Throws:
        NullPointerException - if either iterator is null

      • ZippingIterator

        public ZippingIterator(Iterator<? extends E>... iterators)
        Constructs a new ZippingIterator that will provide interleaved iteration of the specified iterators.
        Parameters:
        iterators - the array of iterators
        Throws:
        NullPointerException - if any iterator is null

    • Method Detail

      • hasNext

        public boolean hasNext()
        Returns true if any child iterator has remaining elements.
        Specified by:
        hasNext in interface  Iterator<E>
        Returns:
        true if this iterator has remaining elements

      • remove

        public void remove()
        Removes the last returned element from the child iterator that produced it.
        Specified by:
        remove in interface  Iterator<E>
        Throws:
        IllegalStateException - if there is no last returned element, or if the last returned element has already been removed