1 package hdfs;
 2 
 3 import java.io.FileNotFoundException;
 4 import java.io.FileOutputStream;
 5 import java.io.IOException;
 6 
 7 import org.apache.commons.compress.utils.IOUtils;
 8 import org.apache.hadoop.conf.Configuration;
 9 import org.apache.hadoop.fs.FSDataInputStream;
10 import org.apache.hadoop.fs.FileSystem;
11 import org.apache.hadoop.fs.Path;
12 
13 /**
14  *  功能：      将 hdfs://ssmaster:9000/data/paper.txt下载到Windows下c:\paper.txt
15  *  调用方式：hadoop jar 打包包名.jar  
16  */
17 
18 public class Down_Load {
19 
20     public static void main(String[] args) {
21         
22     Configuration conf =new Configuration();
23     conf.set("fs.defaultFS", "hdfs://ssmaster:9000/");
24     
25     FileSystem fs = null;
26     Path src = null;
27     FSDataInputStream in = null;
28     FileOutputStream out = null;
29       
30     src = new Path("hdfs://ssmaster:9000/data/paper.txt" );
31     
32     try {
33         
34       fs = FileSystem.get(conf) ;
35       in = fs.open(src);
36 
37        } catch (IOException e) {
38         e.printStackTrace(); 
39     }
40     
41     try {
42         out = new FileOutputStream ("c:\\paper.txt"); //等效  c:/paper.txt
43     } catch (FileNotFoundException e) {
44         e.printStackTrace();
45     }
46     
47     try {
48         IOUtils.copy(in, out);
49     } catch (IOException e) {
50         e.printStackTrace();
51     }
52 
53 }
54 }