CompressionCodec代码片段一则

	import java.io.InputStream;
	import java.net.URI;
	import org.apache.hadoop.conf.Configuration;
	import org.apache.hadoop.fs.FileSystem;
	import org.apache.hadoop.fs.Path;
	import org.apache.hadoop.io.IOUtils;
	import org.apache.hadoop.io.compress.CompressionCodec;
	import org.apache.hadoop.io.compress.CompressionOutputStream;
	import org.apache.hadoop.util.ReflectionUtils;
	//vv StreamCompressorpublic class StreamCompressor 
	{    
	public static void main(String[] args) throws Exception {       
	String codecClassname = "org.apache.hadoop.io.compress.GzipCodec";      
	String uri = "hdfs://master:9000/in/test.txt";      
	String outputUri = "hdfs://master:9000/in/test.txt.gz";             
	Class<?> codecClass = Class.forName(codecClassname);      
	Configuration conf = new Configuration();       
	FileSystem fs1 = FileSystem.get(URI.create(uri), conf);     
	FileSystem fs2 = FileSystem.get(URI.create(outputUri), conf);               
	CompressionCodec codec = (CompressionCodec) ReflectionUtils.newInstance(codecClass, conf);     
	InputStream in =fs1.open(new Path(uri));            
	CompressionOutputStream out = codec.createOutputStream(fs2.create(new Path(outputUri)));                
	IOUtils.copyBytes(in, out, 4096, false);        
	in.close();     
	out.close();    
	}}// ^^ StreamCompressor