How to get the input file name in the mapper in a Hadoop program?

Question

How I can get the name of the input file within a mapper? I have multiple input files stored in the input directory, each mapper may read a different file, and I need to kno

Answer 1

For org.apache.hadood.mapred package the map function signature should be:

map(Object, Object, OutputCollector, Reporter) 

So, to get the file name inside the map function, you could use the Reporter object like this:

String fileName = ((FileSplit) reporter.getInputSplit()).getPath().getName();