Package org.apache.commons.functor.core.collection

Class FilteredIterator<T>

  • Type Parameters:
    T - the Iterator generic type
    All Implemented Interfaces:
    java.util.Iterator<T>
    public final class FilteredIterator<T>
extends java.lang.Object
implements java.util.Iterator<T>
    Iterator that filters another Iterator by only passing through those elements that are matched by a specified UnaryPredicate.
    Version:
    $Revision$ $Date$

    • Field Summary

      Fields 
      Modifier and Type Field Description
      private boolean canRemove
      Flag to mark current iterator element can be removed.
      private java.util.Iterator<? extends T> iterator
      The wrapped iterator.
      private T next
      Reference to next element has to be returned by this iterator.
      private boolean nextSet
      Flag to mark this iterator has more elements or not.
      private UnaryPredicate<? super T> predicate
      The predicate used to test this Iterator elements.

    • Constructor Summary

      Constructors 
      Constructor Description
      FilteredIterator​(java.util.Iterator<? extends T> iterator, UnaryPredicate<? super T> predicate)
      Create a new FilteredIterator.

    • Method Summary

      All Methods Static Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      boolean equals​(java.lang.Object obj)
      static <T> java.util.Iterator<T> filter​(java.util.Iterator<? extends T> iter, UnaryPredicate<? super T> pred)
      Get a filtered Iterator instance applying pred to iter.
      int hashCode()
      boolean hasNext()
      T next()
      void remove()
      private T returnNext()
      Get the next element.
      private boolean setNext()
      Set next element.
      java.lang.String toString()

      • Methods inherited from class java.lang.Object

        clone, finalize, getClass, notify, notifyAll, wait, wait, wait

      • Methods inherited from interface java.util.Iterator

        forEachRemaining

    • Field Detail

      • predicate

        private final UnaryPredicate<? super T> predicate
        The predicate used to test this Iterator elements.

      • iterator

        private final java.util.Iterator<? extends T> iterator
        The wrapped iterator.

      • next

        private T next
        Reference to next element has to be returned by this iterator.

      • nextSet

        private boolean nextSet
        Flag to mark this iterator has more elements or not.

      • canRemove

        private boolean canRemove
        Flag to mark current iterator element can be removed.

    • Constructor Detail

      • FilteredIterator

        public FilteredIterator​(java.util.Iterator<? extends T> iterator,
                        UnaryPredicate<? super T> predicate)
        Create a new FilteredIterator.
        Parameters:
        iterator - to filter
        predicate - to apply

    • Method Detail

      • hasNext

        public boolean hasNext()
        Specified by:
        hasNext in interface java.util.Iterator<T>
        See Also:
        Iterator.hasNext()

      • next

        public T next()
        Specified by:
        next in interface java.util.Iterator<T>
        See Also:
        Iterator.next()

      • remove

        public void remove()
        Specified by:
        remove in interface java.util.Iterator<T>
        See Also:
        Iterator.remove()

      • equals

        public boolean equals​(java.lang.Object obj)
        Overrides:
        equals in class java.lang.Object

      • hashCode

        public int hashCode()
        Overrides:
        hashCode in class java.lang.Object

      • toString

        public java.lang.String toString()
        Overrides:
        toString in class java.lang.Object

      • filter

        public static <T> java.util.Iterator<T> filter​(java.util.Iterator<? extends T> iter,
                                               UnaryPredicate<? super T> pred)
        Get a filtered Iterator instance applying pred to iter.
        Type Parameters:
        T - the input iterator generic type
        Parameters:
        iter - to filter
        pred - to apply
        Returns:
        Iterator

      • setNext

        private boolean setNext()
        Set next element.
        Returns:
        whether the current iterator position is valid

      • returnNext

        private T returnNext()
        Get the next element.
        Returns:
        next element.