Hi Ives, Thanks a lot for your reply. But how should I claim the Map class? Currently I have "public static class Map extends MapReduceBase implements Mapper<BytesWritable, SequenceFile, SequenceFile, BytesWritable>". Does not seem to be right. I am pretty new to this field. Many thanks in advance for your help.
On Fri, Dec 18, 2009 at 11:27 AM, Ives Aerts <[email protected]<ives.aerts%[email protected]> > wrote: > On Fri, Dec 18, 2009 at 5:20 PM, Cao Kang <[email protected]> wrote: > > Is there any example how a sequence file can be read and split in hadoop? > > Many thanks! > > That should be fairly easy. The following code reads all entries in a > sequence file: > > SequenceFile.Reader reader = new > SequenceFile.Reader(path.getFileSystem(config), path, config); > > Writable key = (Writable)reader.getKeyClass().newInstance(); > Writable value = (Writable)reader.getValueClass().newInstance(); > > while(reader.next(key, value)) { > System.out.println(key + "\t" + value); > } > > reader.close(); > > Add some logic to partition the entries and write them out using a > SequenceFile.Writer. > > -- > Cheers, > -Ives >
