A MapFile isn't a directory. It is a directory _containing_ two files. You cannot "open" a directory for reading.
The MapFile API is documented at http://hadoop.apache.org/docs/stable/api/org/apache/hadoop/io/MapFile.html and thats what you're to be using for reading/writing them. Compression is a simple option you need to provide when invoking the writer: http://hadoop.apache.org/docs/stable/api/org/apache/hadoop/io/MapFile.Writer.html#MapFile.Writer(org.apache.hadoop.conf.Configuration,%20org.apache.hadoop.fs.FileSystem,%20java.lang.String,%20org.apache.hadoop.io.WritableComparator,%20java.lang.Class,%20org.apache.hadoop.io.SequenceFile.CompressionType,%20org.apache.hadoop.io.compress.CompressionCodec,%20org.apache.hadoop.util.Progressable) On Sun, Aug 11, 2013 at 1:46 AM, Abhijit Sarkar <[email protected]> wrote: > Hi, > I'm a Hadoop newbie. This is my first question to this mailing list, hoping > for a good start :) > > MapFile is a directory so when I try to open an InputStream to it, it fails > with FileNotFoundException. How do I compress MapFile programmatically? > > Code snippet: > final FileSystem fs = FileSystem.get(conf); > final InputStream inputStream = fs.open(new Path(uncompressedStr)); > > Exception: > java.io.FileNotFoundException: /some/directory (No such file or directory) > at java.io.FileInputStream.open(Native Method) > at java.io.FileInputStream.<init>(FileInputStream.java:120) > at > org.apache.hadoop.fs.RawLocalFileSystem$TrackingFileInputStream.<init>(RawLocalFileSystem.java:71) > at > org.apache.hadoop.fs.RawLocalFileSystem$LocalFSFileInputStream.<init>(RawLocalFileSystem.java:107) > at org.apache.hadoop.fs.RawLocalFileSystem.open(RawLocalFileSystem.java:177) > at > org.apache.hadoop.fs.ChecksumFileSystem$ChecksumFSInputChecker.<init>(ChecksumFileSystem.java:126) > at org.apache.hadoop.fs.ChecksumFileSystem.open(ChecksumFileSystem.java:283) > at org.apache.hadoop.fs.FileSystem.open(FileSystem.java:427) > at name.abhijitsarkar.learning.hadoop.io.IOUtils.compress(IOUtils.java:104) > > Regards, > Abhijit -- Harsh J
