[jira] [Commented] (NUTCH-2851) Random object created and used only once

["ASF GitHub Bot (Jira)" <ji...@apache.org>]

    [ https://issues.apache.org/jira/browse/NUTCH-2851?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17286244#comment-17286244 ] 

ASF GitHub Bot commented on NUTCH-2851:
---------------------------------------

lewismc opened a new pull request #571:
URL: https://github.com/apache/nutch/pull/571


   This PR addresses https://issues.apache.org/jira/browse/NUTCH-2851
   I chose the following proposed fix...
   
   Create a constant Random in the offending class
   ```
   private static final Random RANDOM = new Random();
   ```
   We then reuse as follows
   ```
   RANDOM.nextInt();
   ```
   This way, no new instances are created.


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> Random object created and used only once
> ----------------------------------------
>
>                 Key: NUTCH-2851
>                 URL: https://issues.apache.org/jira/browse/NUTCH-2851
>             Project: Nutch
>          Issue Type: Sub-task
>          Components: dmoz, generator, indexer, segment
>    Affects Versions: 1.18
>            Reporter: Lewis John McGibbney
>            Assignee: Lewis John McGibbney
>            Priority: Major
>             Fix For: 1.19
>
>
> In class org.apache.nutch.crawl.Generator
> In method org.apache.nutch.crawl.Generator.partitionSegment(Path, Path, int)
> Called method java.util.Random.nextInt()
> At Generator.java:[line 1016]
> Random object created and used only once in org.apache.nutch.crawl.Generator.partitionSegment(Path, Path, int)
> This code creates a java.util.Random object, uses it to generate one random number, and then discards the Random object. This produces mediocre quality random numbers and is inefficient. If possible, rewrite the code so that the Random object is created once and saved, and each time a new random number is required invoke a method on the existing Random object to obtain it.
> If it is important that the generated Random numbers not be guessable, you must not create a new Random for each random number; the values are too easily guessable. You should strongly consider using a java.security.SecureRandom instead (and avoid allocating a new SecureRandom for each random number needed).
> This bad practice also affects the following
> org.apache.nutch.indexer.IndexingJob since first historized release
> org.apache.nutch.segment.SegmentReader since first historized release
> org.apache.nutch.tools.DmozParser$RDFProcessor since first historized release 



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