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From Varene Olivier <var...@echo.fr>
Subject Re: passing dependencies to my Mapper
Date Tue, 15 Sep 2009 15:44:36 GMT
Just my two cents, but, if your ressources can be intantiated at 
configuration time, you can use the "configure" method from 
MapperReduceBase Object to assign your local static objects with the 
values taken from the job configuration object


public class Normalize_Reduce extends MapReduceBase implements
			Reducer<..., ..., ..., ...>
{
	private ... ;

	// Methode to get back some knowledge about your Job conf
	public void configure(JobConf job)
	{
	}

	//
	public void reduce(... p_key, Iterator<...> p_values,
				OutputCollector<..., ...> output, Reporter reporter)
				throws IOException
	{
	}

}

I might have not understood your needs, but hope it helps



Lowell Kirsh a écrit :
> I have a Mapper class which needs access to several dependencies (such 
> as a db). It seems that because the framework is new'ing up instances of 
> my Mapper class, I have little control over its lifecycle. Up to now, 
> I've been setting them up as static fields in that class, which is not 
> ideal. Is there a better way to inject my dependencies?
> 
> Thanks,
> Lowell

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