java调用API操作HDFS

package mongodb;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.net.URI;
import java.util.Arrays;

import org.apache.commons.lang.StringUtils;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.FSDataInputStream;
import org.apache.hadoop.fs.FileStatus;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.io.compress.CompressionCodec;
import org.apache.hadoop.io.compress.CompressionCodecFactory;
import org.apache.hadoop.io.compress.CompressionInputStream;
import org.apache.hadoop.util.ReflectionUtils;


class Item implements Comparable
{
	String value;
	double weight;
	public Item(String v)
	{
		value=v;
		weight = Double.parseDouble(value.split(":")[1]);
	}
	public int compareTo(Object o)
	{   
       return this.weight == ((Item) o).weight ? 0 :  
           (this.weight  > ((Item) o).weight ? -1 : 1); 
   } 
}

public class BatchUpdateSim {
	public static String parse(String str)
	{
		//String str="90003	20718001:1.0,2077635:1.0,2053809:1.0";
		String[] fields=str.split("\t");
		String[] valueArray= fields[1].split(",");
		Item[] items = new Item[valueArray.length];
		for(int i=0;i<items.length;i++)
		{
			items[i]=new Item(valueArray[i]);
		}
		Arrays.sort(items);
		for(int i=0;i<valueArray.length;i++)
		{
			valueArray[i] = "{"+items[i].value+"}";
		}
		String valueStr = StringUtils.join(valueArray,",");
		return  "{\"key\":"+fields[0]+",\"values\":["+valueStr+"]}";
				
	}
	public static void main(String[] args) throws IOException, ClassNotFoundException {
		// TODO Auto-generated method stub

		Configuration  conf = new Configuration ();  
	  conf.addResource("/usr/local/hadoop/conf/core-site.xml");
	  conf.addResource("/usr/local/hadoop/conf/hdfs-site.xml");
	   conf.addResource("/usr/local/hadoop/conf/mapred-site.xml");
		//String HDFS="hdfs://webdm-cluster";
		//String HDFS="hdfs://localhost:9000";
	    String HDFS=args[0];
		FileSystem hdfs = FileSystem.get(URI.create(HDFS),conf); 
		String filePath=args[1];
		FSDataInputStream fin = hdfs.open(new Path(filePath));

		//CompressionCodecFactory factory = new CompressionCodecFactory(conf);  
		//CompressionCodec codec = factory.getCodec(new Path(filePath)); //依据hdfs文件的后缀类型主动辨认
		//Class<?> codecClass = Class.forName("com.hadoop.compression.lzo.LzoCodec");
		//CompressionCodec codec = (CompressionCodec)ReflectionUtils.newInstance(codecClass, conf);
        BufferedReader reader = null;
		String line;
		int count=0;
		RecsysDb db = RecsysDb.getInstance();
		String itemSimName=args[2];
		try 
		{
			// if (codec == null)
			// {  
			        reader = new BufferedReader(new InputStreamReader(fin)); // in = new BufferedReader(new InputStreamReader(fin, "UTF-8"));				    
			// }
			        /*
			 else 
			 {  
				    System.out.println("辨认出紧缩类型");
			        CompressionInputStream comInputStream = codec.createInputStream(fin);  
			        reader = new BufferedReader(new InputStreamReader(comInputStream));  
			  } */
			 		
			while ((line = reader.readLine()) != null) 
			{
				//if(count==0) System.out.println(line);
				String strJson=parse(line);
				
				db.updateItemSim(itemSimName, strJson);
				count++;
				if(count%1000==0)System.out.println("count:"+count);
			}	
		} 
		finally 
		{
			if (reader != null) 
			{
				reader.close();
			}
			System.out.println(count);
			
		}
		

	}

}
packag