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From Jonathan Poon <jkp...@ucdavis.edu>
Subject Re: Hadoop 2.2.0 Distributed Cache
Date Thu, 27 Mar 2014 16:20:17 GMT
Hi Stanley,

Sorry about the confusion, but I'm trying to read a txt file into my Mapper
function.  I am trying to copy the file using the -files option when
submitting the Hadoop job.

I try to obtain the filename using the following lines of code in my Mapper:

URI[] localPaths = context.getCacheFiles();
String configFilename = localPaths[0].toString();

However, when I run the JAR in hadoop, I get a NullPointerException.

Error: java.lang.NullPointerException

I'm running Hadoop 2.2 in Single Node mode.  Not sure if that affects

On Wed, Mar 26, 2014 at 8:21 PM, Stanley Shi <sshi@gopivotal.com> wrote:

> where did you get the error? from the compiler or the runtime?
> Regards,
> *Stanley Shi,*
> On Thu, Mar 27, 2014 at 7:34 AM, Jonathan Poon <jkpoon@ucdavis.edu> wrote:
>> Hi Everyone,
>> I'm submitting a MapReduce job using the -files option to copy a text
>> file that contains properties I use for the map and reduce functions.
>> I'm trying to obtain the local cache files in my mapper function using:
>> Path[] paths = context.getLocalCacheFiles();
>> However, i get an error saying getLocalCacheFiles() is undefined.  I've
>> imported the hadoop-mapreduce-client-core-2.2.0.jar as part of my build
>> environment in Eclipse.
>> Any ideas on what could be incorrect?
>> If I'm incorrectly using the distributed cache, could someone point me to
>> an example using the distributed cache with Hadoop 2.2.0?
>> Thanks for your help!
>> Jonathan

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