通过FileSystem API读取数据

package com.lcy.hadoop.file;

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;

public class FileSystemCat {

    public static void main(String[] args) throws Exception{
        // TODO Auto-generated method stub
        String uri=args[0];
        Configuration conf=new Configuration();
        FileSystem fs=FileSystem.get(URI.create(uri),conf);
        InputStream in=null;
        try{
            in=fs.open(new Path(uri));
            IOUtils.copyBytes(in, System.out, 4096,false);
        }finally{
            IOUtils.closeStream(in);
        }
    }
}