Package org.apache.commons.collections4.iterators

Class ZippingIterator<E>

java.lang.Object
org.apache.commons.collections4.iterators.ZippingIterator<E>
Type Parameters:
E - the type of elements returned by this iterator.
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
    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.

  • Method Summary

    Modifier and Type
    Method
    Description
    boolean
    hasNext()
    Returns true if any child iterator has remaining elements.
    E
    next()
    Returns the next element from a child iterator.
    void
    remove()
    Removes the last returned element from the child iterator that produced it.

    Methods inherited from class java.lang.Object

    clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

    Methods inherited from interface java.util.Iterator

    forEachRemaining

  • Constructor Details

    • 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

    • 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

  • Method Details

    • 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

    • next

      public E next() throws NoSuchElementException
      Returns the next element from a child iterator.
      Specified by:
      next in interface Iterator<E>
      Returns:
      the next interleaved element
      Throws:
      NoSuchElementException - if no child iterator has any more 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