Mailing-List: contact issues-help@commons.apache.org; run by ezmlm
Precedence: bulk
Reply-To: issues@commons.apache.org
Date: Sun, 3 Jun 2012 11:21:23 +0000 (UTC)
From: "Thomas Neidhart (JIRA)" <jira@apache.org>
To: issues@commons.apache.org
Message-ID: <1968720014.31585.1338722483153.JavaMail.jiratomcat@issues-vm>
In-Reply-To: 
 <650766491.1311.1311018717863.JavaMail.tomcat@hel.zones.apache.org>
Subject: [jira] [Resolved] (COLLECTIONS-377) CollatingIterator throws
 NullPointerException when constructor is given null (or no) Comparator
MIME-Version: 1.0
Content-Type: text/plain; charset=utf-8
Content-Transfer-Encoding: 7bit


     [ https://issues.apache.org/jira/browse/COLLECTIONS-377?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]

Thomas Neidhart resolved COLLECTIONS-377.
-----------------------------------------

       Resolution: Duplicate
    Fix Version/s: 4.0

This has been fixed as part of [COLLECTIONS-331]. Now the javadoc states that a comparator *must* be provided (either via constructor or by calling setComparator afterwards) before using the iterator.
                
> CollatingIterator throws NullPointerException when constructor is given null (or no) Comparator
> -----------------------------------------------------------------------------------------------
>
>                 Key: COLLECTIONS-377
>                 URL: https://issues.apache.org/jira/browse/COLLECTIONS-377
>             Project: Commons Collections
>          Issue Type: Bug
>          Components: Iterator
>    Affects Versions: 3.2
>         Environment: Java 1.6.0_26
>            Reporter: Ryan Hochstetler
>            Priority: Minor
>             Fix For: 4.0
>
>
> CollatingIterator's javadoc (http://commons.apache.org/collections/api-release/index.html) states that natural sort ordering will be used when null is passed as the Comparator argument to any of the constructors accepting one (and for the nullary constructor).  The following stack is thrown from the subsequent unit test.  The implementation of least() does not appear to account for the natural sort order case.
> java.lang.NullPointerException
> 	at org.apache.commons.collections.iterators.CollatingIterator.least(CollatingIterator.java:334)
> 	at org.apache.commons.collections.iterators.CollatingIterator.next(CollatingIterator.java:230)
> 	at mil.af.statistics.jutl.collection.MutableDataSeriesTest...
>     @SuppressWarnings("unchecked")
>     @Test
>     public void testCollatingIteratorNaturalOrdering() throws Exception
>     {
>         Integer[] expected =
>         { Integer.valueOf(1), Integer.valueOf(2), Integer.valueOf(3), Integer.valueOf(4), Integer.valueOf(5),
>             Integer.valueOf(6) };
>         List<Integer> evens = Arrays.asList(new Integer[]
>         { Integer.valueOf(2), Integer.valueOf(4), Integer.valueOf(6) });
>         List<Integer> odds = Arrays.asList(new Integer[]
>         { Integer.valueOf(1), Integer.valueOf(3), Integer.valueOf(5) });
>         Iterator<Integer> collatingIter = new CollatingIterator(null, evens.iterator(), odds.iterator());
>         for (Integer expectedInt : expected)
>         {
>             assertTrue(collatingIter.hasNext());
>             assertEquals(expectedInt, collatingIter.next());
>         }
>     }
> Workaround: provide a Comparator that implements the natural ordering contract.

--
This message is automatically generated by JIRA.
If you think it was sent incorrectly, please contact your JIRA administrators: https://issues.apache.org/jira/secure/ContactAdministrators!default.jspa
For more information on JIRA, see: http://www.atlassian.com/software/jira