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https://issues.apache.org/jira/browse/HADOOP-9424?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13609152#comment-13609152
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Colin Patrick McCabe commented on HADOOP-9424:
----------------------------------------------

This looks reasonable.  I can't think of any reason we wouldn't want to put the 
passed jar on the classpath before invoking RunJar.
                
> The "hadoop jar" invocation should include the passed jar on the classpath as 
> a whole
> -------------------------------------------------------------------------------------
>
>                 Key: HADOOP-9424
>                 URL: https://issues.apache.org/jira/browse/HADOOP-9424
>             Project: Hadoop Common
>          Issue Type: Bug
>          Components: util
>    Affects Versions: 2.0.3-alpha
>            Reporter: Harsh J
>            Assignee: Harsh J
>            Priority: Minor
>         Attachments: HADOOP-9424.patch
>
>
> When you have a case such as this:
> {{X.jar -> Classes = Main, Foo}}
> {{Y.jar -> Classes = Bar}}
> With implementation details such as:
> * Main references Bar and invokes a public, static method on it.
> * Bar does a class lookup to find Foo (Class.forName("Foo")).
> Then when you do a {{HADOOP_CLASSPATH=Y.jar hadoop jar X.jar Main}}, the 
> Bar's method fails with a ClassNotFound exception cause of the way RunJar 
> runs.
> RunJar extracts the passed jar and includes its contents on the ClassLoader 
> of its current thread but the {{Class.forName(…)}} call from another class 
> does not check that class loader and hence cannot find the class as its not 
> on any classpath it is aware of.
> The script of "hadoop jar" should ideally include the passed jar argument to 
> the CLASSPATH before RunJar is invoked, for this above case to pass.

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