通过idea测试Hadoop增删改查

  1 package day01;
  2 
  3 import org.apache.hadoop.conf.Configuration;
  4 import org.apache.hadoop.fs.*;
  5 
  6 import java.io.*;
  7 import java.net.URI;
  8 
  9 /**
 10  * @autho 通过idea进行hadoop测试增删改查
 11  * @create 2019-09-16 14:15
 12  **/
 13 public class HadoopClients {
 14 
 15    static FileSystem fileSystem = null;
 16 
 17     public static void main(String[] args) throws Exception {
 18         /*mkdir();*/
 19 
 20         /*mv();*/
 21 
 22        /* rm();*/
 23 
 24         /*up();*/
 25 
 26         /*see();*/
 27 
 28         readWrite();
 29     }
 30 
 31     //静态代码块
 32 
 33     static {
 34         Configuration conf = new Configuration();
 35         //hadoop的链接对象
 36         try {
 37              fileSystem = FileSystem.get(new URI("hdfs://hadoop01:9000"),conf,"root");
 38         } catch (Exception e) {
 39             e.printstacktrace();
 40         }
 41     }
 42     //创建目录
 43     public static void mkdir() throws Exception{
 44             fileSystem.mkdirs(new Path("/test1"));
 45             System.out.println("创建成功！！");
 46     }
 47 
 48     //修改目录
 49     public static void mv() throws Exception{
 50         fileSystem.rename(new Path("/test1"),new Path("/test2"));
 51         System.out.println("修改成功！！");
 52     }
 53 
 54     //删除目录
 55     public static void rm() throws Exception{
 56         fileSystem.delete(new Path("/test2"),true);
 57         System.out.println("删除成功！！");
 58     }
 59 
 60     //上传数据
 61     public static void up() throws Exception{
 62         fileSystem.copyFromLocalFile(new Path("B:\\wc.txt"),new Path("/beida"));
 63         System.out.println("上传成功！！");
 64     }
 65 
 66     //查看目录
 67     public static void see() throws Exception{
 68         RemoteIterator<LocatedFileStatus> iterator = fileSystem.listFiles(new Path("/"), true);
 69         //迭代器取数据
 70         while (iterator.hasNext()){
 71             LocatedFileStatus next = iterator.next();
 72             System.out.println(next.getPath());
 73             System.out.println(next.getLen());
 74             System.out.println(next.getBlockSize());
 75             System.out.println(next.getReplication());
 76             System.out.println("-------------------------------------");
 77         }
 78     }
 79     
 80     //模拟数据的读写
 81     public static void readWrite() throws Exception{
 82         
 83         FSDataInputStream open = fileSystem.open(new Path("/beida/wc.txt"));
 84 
 85         FSDataOutputStream create = fileSystem.create(new Path("/result.txt"));
 86         
 87         //要把IO流数据转化为String类型
 88         BufferedReader br = new BufferedReader(new InputStreamReader(open));
 89         BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(create));
 90         //处理数据
 91         String line = null;
 92         //br.readLine!==null是判断有没有数据
 93         while ((line=br.readLine())!=null){
 94             String[] words = line.split(",");
 95             //数据写出去
 96             bw.write(line);
 97             bw.newLine();
 98             bw.flush();
 99         }
100         System.out.println("写出成功！！");
101         //关闭
102         br.close();
103         bw.close();
104     }
105 }