向HDFS中上传任意文本文件,如果指定的文件在HDFS中已经存在,由用户指定是追加到原有文件末尾还是覆盖原有的文件

 1 import java.io.FileInputStream;
 2 import java.io.IOException;
 3 import java.util.Scanner;
 4
 5 import org.apache.hadoop.conf.Configuration;
 6 import org.apache.hadoop.fs.FSDataOutputStream;
 7 import org.apache.hadoop.fs.FileSystem;
 8 import org.apache.hadoop.fs.Path;
 9
10 public class A_UpdatedFile {
11
12
13     public static void appendToFile(FileSystem fs, String localFilePath,
14             String remoteFilePath) {
15         Path remotePath = new Path(remoteFilePath);
16         try {
17             FileInputStream in = new FileInputStream(localFilePath);
18             FSDataOutputStream out = fs.append(remotePath);
19             byte[] data = new byte[1024];
20             int read = -1;
21             while ((read = in.read(data)) > 0) {
22                 out.write(data, 0, read);
23             }
24             out.close();
25         } catch (IOException e) {
26             e.printStackTrace();
27         }
28     }
29
30     public static void main(String[] args) {
31         Var_init var = new Var_init();
32         try {
33             boolean fileExists = var.fs.exists(var.p_remoteFilePath);
34             if (fileExists) {
35                 System.out.println(var.s_remoteFilePath + " 已存在.");
36             } else {
37                 System.out.println(var.s_remoteFilePath + " 不存在.");
38             }
39             if (!fileExists) {
40                 var.fs.copyFromLocalFile(false, true, var.p_localFilePath, var.p_remoteFilePath);
41                 System.out.println(var.s_localFilePath + " 已上传至 "
42                         + var.s_remoteFilePath);
43             } else {
44                 Scanner choose = new Scanner(System.in);
45                 System.out.println("input c to cover,input a to append");
46                 String str = choose.next();
47                 if(str.equals("c"))
48                 {
49                     var.fs.copyFromLocalFile(false, true, var.p_localFilePath, var.p_remoteFilePath);
50                     System.out.println("cover successfully");
51                 }
52                 else if(str.equals("a"))
53                 {
54                     A_UpdatedFile.appendToFile(var.fs, var.s_localFilePath, var.s_remoteFilePath);
55                     System.out.println("append successfully");
56                 }
57                 else
58                 {
59                     System.out.println("plz input right common");
60                 }
61             }
62         } catch (Exception e) {
63             e.printStackTrace();
64         }
65     }
66 }

Var_init类参考https://www.cnblogs.com/MiraculousB/p/13848744.html