Treat an Iterator as an Iterable

     
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import java.io.Serializable;
import java.util.AbstractMap;
import java.util.AbstractSet;
import java.util.Collection;
import java.util.Enumeration;
import java.util.Iterator;
import java.util.Map;
import java.util.NoSuchElementException;
import java.util.Set;

/**
 * @since 4.37
 * @author Jaroslav Tulach
 */


public class Utils {
  /**
   * Treat an {@link Iterator} as an {@link Iterable} so it can be used in an enhanced for-loop.
   * Bear in mind that the iterator is "consumed" by the loop and so should be used only once.
   * Generally it is best to put the code which obtains the iterator inside the loop header.
   * <div class="nonnormative">
   * <p>Example of correct usage:</p>
   * <pre>
   * String text = ...;
   * for (String token : NbCollections.iterable(new {@link java.util.Scanner}(text))) {
   *     // ...
   * }
   * </pre>
   * </div>
   * @param iterator an iterator
   * @return an iterable wrapper which will traverse the iterator once
   * @throws NullPointerException if the iterator is null
   * @see <a href="http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=6312085">Java bug #6312085</a>
   * @see <a href="http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=6360734">Java bug #6360734</a>
   * @see <a href="http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=4988624">Java bug #4988624</a>
   * @since org.openide.util 7.5
   */
  public static <E> Iterable<E> iterable(final Iterator<E> iterator) {
      if (iterator == null) {
          throw new NullPointerException();
      }
      return new Iterable<E>() {
          public Iterator<E> iterator() {
              return iterator;
          }
      };
  }

}

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2.	De-mystify the Iterator interface, showing how to write a simple Iterator for an Array of Objects
3.	Iterate over Set
4.	Demonstrate iterators.
5.	Use the for-each for loop to cycle through a collection.
6.	List Iterator
7.	Iterate a Collection and remove an item (Exception, wrong version)
8.	Use an Iterator and remove the item with Iterator.remove()
9.	An Iterator wrapper for an Enumeration.
10.	EmptyIterator is an iterator which is empty.
11.	Implements an java.util.Iterator over any array
12.	Iterator class for sparse values in an array.
13.	Iterator class for values contained in an array range.
14.	Array Iterator
15.	Cyclic Iteration
16.	Create singleton Iterator
17.	Empty Iterator
18.	An Iterator that wraps a number of Iterators
19.	An Iterator to iterate over the elements of an array
20.	Sorted Iterator
21.	Iterator Union of Iterators
22.	Iterator Utils
23.	Linked Iterator
24.	Prefetch Iterator
25.	Protects an given iterator by preventing calls to remove().
26.	An Iterator that returns the elements of a specified array, or other iterators etc.
27.	An Iterator wrapper for an Object[], allow us to deal with all array like structures in a consistent manner.
28.	An array iterator
29.	Adapt iterator to iterable
30.	Static utility methods, classes, and abstract classes for iteration.
31.	Iterator Collection
32.	Convert Iterable to List
33.	A singleton null object Iterator implementation.

Treat an Iterator as an Iterable : Iterator « Collections Data Structure « Java

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