commons-issues mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Sebb (JIRA)" <j...@apache.org>
Subject [jira] Commented: (LANG-472) RandomUtils.nextLong() get all even number
Date Thu, 04 Feb 2010 01:40:28 GMT

    [ https://issues.apache.org/jira/browse/LANG-472?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12829378#action_12829378
] 

Sebb commented on LANG-472:
---------------------------

Applied Phil's patch, but adjusted so that the class now uses a static Random() instance for
all random number generation.

URL: http://svn.apache.org/viewvc?rev=906318&view=rev
Log:
LANG-472 - RandomUtils.nextLong() get all even number

Modified:
   commons/proper/lang/branches/LANG_2_X/src/main/java/org/apache/commons/lang/math/JVMRandom.java
   commons/proper/lang/branches/LANG_2_X/src/test/java/org/apache/commons/lang/math/RandomUtilsTest.java

I suspect nextLong(long) probably does not generate very evenly distributed numbers.

Also documented non-negative behaviour:

URL: http://svn.apache.org/viewvc?rev=906319&view=rev
Log:
LANG-472 - Document >=0 behaviour

Modified:
   commons/proper/lang/branches/LANG_2_X/src/main/java/org/apache/commons/lang/math/JVMRandom.java



> RandomUtils.nextLong() get all even number
> ------------------------------------------
>
>                 Key: LANG-472
>                 URL: https://issues.apache.org/jira/browse/LANG-472
>             Project: Commons Lang
>          Issue Type: Bug
>          Components: lang.math.*
>         Environment: all system
>            Reporter: zhangruimin
>             Fix For: 2.x
>
>         Attachments: lang-472.patch
>
>
> when we use the following code , we can see that the method produce only even number.
>          while (true) {
> //        for (int i = 0; i < 100; i++) {
>             if (RandomUtils.nextLong() % 2 == 1) {
>                 System.out.println("ok");
>             }
>         }

-- 
This message is automatically generated by JIRA.
-
You can reply to this email to add a comment to the issue online.


Mime
View raw message