Is there a reason why MapFile.Reader/Writer constructors take a String for
dirName instead of a Path?  This seems inconsistent with
SequenceFile.Reader/Writer.

Also the order of arguments changes (conf then fs, or fs then conf).

I suppose these might just be backwards compat reasons?

http://hadoop.apache.org/docs/r1.0.4/api/org/apache/hadoop/io/MapFile.Reader.html#MapFile.Reader%28org.apache.hadoop.fs.FileSystem,%20java.lang.String,%20org.apache.hadoop.conf.Configuration%29

http://hadoop.apache.org/docs/r1.0.4/api/org/apache/hadoop/io/MapFile.Writer.html#MapFile.Writer%28org.apache.hadoop.conf.Configuration,%20org.apache.hadoop.fs.FileSystem,%20java.lang.String,%20java.lang.Class,%20java.lang.Class%29

http://hadoop.apache.org/docs/r1.0.4/api/org/apache/hadoop/io/SequenceFile.Reader.html#SequenceFile.Reader%28org.apache.hadoop.fs.FileSystem,%20org.apache.hadoop.fs.Path,%20org.apache.hadoop.conf.Configuration%29

http://hadoop.apache.org/docs/r1.0.4/api/org/apache/hadoop/io/SequenceFile.Writer.html#SequenceFile.Writer%28org.apache.hadoop.fs.FileSystem,%20org.apache.hadoop.conf.Configuration,%20org.apache.hadoop.fs.Path,%20java.lang.Class,%20java.lang.Class%29