Unzipping from external filesystem to HDFS

[Per Steffensen]

Hi

I want to unzip a file that is living on an external (external from 
HDFS) filesystem to HDFS, so that the unzipped files end up in some 
folder on the HDFS. This needs to be as efficient as possible - so e.g. 
if it is done i java code it probably needs to involve java.nio.channels 
stuff or something that works directly with I/O resources. Can anyone 
point me to the best/easiest/most efficient way to do this? I would like 
to at least be able to invoke/initiate the unzip-process from java code, 
but I guess I can invoke anything from java, so that is not much of a 
requirement.

Regards, Per Steffensen