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Hadoop, mail # user - The method setMapperClass(Class<? extends Mapper>) in the type Job is not applicable for the arguments


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Re: The method setMapperClass(Class<? extends Mapper>) in the type Job is not applicable for the arguments
Ronan Lehane 2013-02-09, 18:44
Thanks for that Harsh.
I just have standard compilation errors now that I'll need to look into.
Thanks for the help, I don't think I would have ever figured that one out.

Cheers

On Sat, Feb 9, 2013 at 6:40 PM, Ronan Lehane <[EMAIL PROTECTED]> wrote:

> Hi Harsh,
>
> Yep I'm using Eclipse.
> I've edited the line below but I'm still getting the same error.
> I'll chance it outside of eclipse from the command line and see what
> happens.
>
> Thanks.
>
> On Sat, Feb 9, 2013 at 6:35 PM, Harsh J <[EMAIL PROTECTED]> wrote:
>
>> Your import line of Mapper has the issue. It is imported as below,
>> which can probably be removed as it is unnecessary:
>>
>> import org.apache.hadoop.mapreduce.Mapper.Context;
>>
>> But you also would need the line below for the actual class to get found:
>>
>> import org.apache.hadoop.mapreduce.Mapper;
>>
>> Adding that line to your list of imports should help resolve it.
>>
>> I recall some IDEs being odd about these things sometimes, and not
>> reporting the real error correctly. Were you using one? Eclipse?
>>
>> On Sat, Feb 9, 2013 at 11:47 PM, Ronan Lehane <[EMAIL PROTECTED]>
>> wrote:
>> > Hi Harsh,
>> >
>> > Thanks for getting back so quickly.
>> >
>> > The full source code is attached as there's nothing sensitive in it.
>> > Coding wouldn't be my strong point so apologies in advance if it looks a
>> > mess.
>> >
>> > Thanks
>> >
>> >
>> > On Sat, Feb 9, 2013 at 6:09 PM, Harsh J <[EMAIL PROTECTED]> wrote:
>> >>
>> >> Whatever "csatAnalysis.MapClass" the compiler picked up, it appears to
>> >> not be extending the org.apache.hadoop.mapreduce.Mapper class. From
>> >> your snippets it appears that you have it all defined properly though.
>> >> A common issue here has also been that people accidentally import the
>> >> wrong API (mapred.*) but that doesn't seem to be the case either.
>> >>
>> >> Can you post your full compilable source somewhere? Remove any logic
>> >> you don't want to share - we'd mostly be interested in the framework
>> >> definition parts alone.
>> >>
>> >> On Sat, Feb 9, 2013 at 11:27 PM, Ronan Lehane <[EMAIL PROTECTED]>
>> >> wrote:
>> >> > Hi All,
>> >> >
>> >> > I hope this is the right forum for this type of question so my
>> apologies
>> >> > if
>> >> > not.
>> >> >
>> >> > I'm looking to write a map reduce program which is giving me the
>> >> > following
>> >> > compilation error:
>> >> > The method setMapperClass(Class<? extends Mapper>) in the type Job is
>> >> > not
>> >> > applicable for the arguments (Class<csatAnalysis.MapClass>)
>> >> >
>> >> > The components involved are:
>> >> >
>> >> > 1. Setting the Mapper
>> >> >         //Set the Mapper for the job. Calls MapClass.class
>> >> >         job.setMapperClass(MapClass.class);
>> >> >
>> >> > 2. Setting the inputFormat to TextInputFormat
>> >> >         //An InputFormat for plain text files. Files are broken into
>> >> > lines.
>> >> >         //Either linefeed or carriage-return are used to signal end
>> of
>> >> > line.
>> >> >         //Keys are the position in the file, and values are the line
>> of
>> >> > text..
>> >> >         job.setInputFormatClass(TextInputFormat.class);
>> >> >
>> >> > 3. Taking the data into the mapper and processing it
>> >> >     public static class MapClass extends Mapper<LongWritable, Text,
>> >> > Text,
>> >> > VectorWritable> {
>> >> >         public void map (LongWritable key, Text value,Context
>> context)
>> >> > throws IOException, InterruptedException {
>> >> >
>> >> > Would anyone have any clues as to what would be wrong with the
>> >> > arguements
>> >> > being passed to the Mapper?
>> >> >
>> >> > Any help would be appreciated,
>> >> >
>> >> > Thanks.
>> >>
>> >>
>> >>
>> >> --
>> >> Harsh J
>> >
>> >
>>
>>
>>
>> --
>> Harsh J
>>
>
>