用程序对hdfs进行操作。

package com.pzoom.hdfs;
import java.io.BufferedInputStream;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.net.URI;
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.IOUtils;
import org.apache.hadoop.util.Progressable;

public class PutFileToHdfs {

 

	/**
	 * 从HDFS上读取文件
	 */
	private static void readFromHdfs() throws FileNotFoundException,
			IOException {
		String dst = "hdfs://ubuntu:9000/";
		Configuration conf = new Configuration();
		FileSystem fs = FileSystem.get(URI.create(dst), conf);
		String path = "/README.txt";
		FSDataInputStream hdfsInStream = fs.open(new Path(path));
		IOUtils.copyBytes(hdfsInStream, System.out, conf, true);
/*		OutputStream out = new FileOutputStream("/home/chenlongquan/output");
		byte[] ioBuffer = new byte[1024];
		int readLen = hdfsInStream.read(ioBuffer);
		while (-1 != readLen) {
			out.write(ioBuffer, 0, readLen);
			readLen = hdfsInStream.read(ioBuffer);
		}
		out.close();
		hdfsInStream.close();
		fs.close();
*/	}

 
	 
	/**
	 * main函数
	 * 
	 * @param args
	 * @throws Exception
	 */
	public static void main(String[] args) throws Exception {
		try {
			//uploadToHdfs();
			readFromHdfs();
			 
		} catch (Exception e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		} finally {
			 
		}
	}

}