Re: Provide context to map function

[Abhinav M Kulkarni]

Thanks all who replied.

I was accidentally using old API hence could not find context argument 
to the map function.

This is solved.

On 04/02/2013 01:20 AM, Dino Kečo wrote:

You should check multiple input format class which enables you to have 
more input formats for same mapper.

Regards,
Dino

On Apr 2, 2013 9:49 AM, "Yanbo Liang" <yanboha...@gmail.com 
<mailto:yanboha...@gmail.com>> wrote:

    protected void map(KEYIN key, VALUEIN value,
                         Context context) throws IOException,
    InterruptedException {
        context.write((KEYOUT) key, (VALUEOUT) value);
      }

    Context is a parameter that the execute environment will pass to
    the map() function.
    You can just use it in the map() function.


    2013/4/2 Abhinav M Kulkarni <abhinavkulka...@gmail.com
    <mailto:abhinavkulka...@gmail.com>>

        To be precise, I am using Hadoop 1.0.4.

        There is no local variable or argument named context in the
        map function.

        Thanks,
        Abhinav


        On 04/01/2013 09:06 PM, Azuryy Yu wrote:
        I supposed your input splits are FileSplit, if not, you need to:

        InputSplit split = context.getInputSplit();

        if (split instanceof FileSplit){
          Path path = ((FileSplit)split).getPath();
        }




        On Tue, Apr 2, 2013 at 12:02 PM, Azuryy Yu
        <azury...@gmail.com <mailto:azury...@gmail.com>> wrote:

            In your map function add following:

            Path currentInput =
            ((FileSplit)context.getInputSplit()).getPath();

            then:

            if (currentInput is first ){
            ................
            }
            else{
            ..................
            }




            On Tue, Apr 2, 2013 at 11:55 AM, Abhinav M Kulkarni
            <abhinavkulka...@gmail.com
            <mailto:abhinavkulka...@gmail.com>> wrote:

                Hi,

                I have a following scenario:

                  * Two mappers (acting on two different files) and
                    one reducer
                  * The mapper code for two different files is the
                    same, except for minor change which depends on
                    which file is being read
                  * Essentially assume there is an if statement - if
                    first file is being read do this else do this

                So how do I provide this context to map function i.e.
                file name or say a boolean flag variable indicating
                the file being read?

                Thanks,
                Abhinav