Input file name in the mapper in a Hadoop program

Question

I want the name of the input file within a mapper. There are multiple input files stored in the input directory, each mapper may read a different file, and I need to know which file the mapper has read.

Answer 1

Try this inside your mapper :

FileSplit fileSplit = (FileSplit)context.getInputSplit();
String filename = fileSplit.getPath().getName();

Try this to do it inside configure() through the old API :

String fileName = new String();
public void configure(JobConf job)
{
   filename = job.get("map.input.file");
}