HDSF中的 API的使用

1.根目錄中文件的遍歷

public static  void  list()throws Exception{
   //1.創建客戶端或者服務器
    Configuration conf = new Configuration() ;
    //2.和hadoop連接起來
    FileSystem hdfs=FileSystem.get(new URI("hdfs://192.168.100.251:8020"),conf);
    //3.獲取某一目錄下的所有文件
    FileStatus[] fileStatuses = hdfs.listStatus(new Path("/"));
    //4.遍歷輸出
    for (FileStatus fileStatus : fileStatuses) {
        System.out.println(fileStatus.getPath().toString());
        hdfs.close();
    }
}

2.文件夾的創建

public static String  mkdir()throws Exception{
        Configuration conf=new Configuration();
        FileSystem hdfs=FileSystem.get(new URI("hdfs://192.168.100.251:8020"),conf);
        boolean mkdirs = hdfs.mkdirs(new Path("/wwfeifeisxsasdas"));
        if (mkdirs){
            return "成功";
        }else {
            return "失敗";
        }

    }

 

3.文件的創建和內容的寫入

 public static void touch()throws Exception{
        Configuration configuration=new Configuration();
        FileSystem hdfs=FileSystem.get(new URI("hdfs://192.168.100.251:8020"),configuration);
        FSDataOutputStream outputStream = hdfs.create(new Path("/home/lz.txt"));
        outputStream.writeUTF("hello word");
        outputStream.flush();
        outputStream.close();
    }

4.文件的刪除

 public static void touch()throws Exception{
        Configuration configuration=new Configuration();
        FileSystem hdfs=FileSystem.get(new URI("hdfs://192.168.100.251:8020"),configuration);
        FSDataOutputStream outputStream = hdfs.create(new Path("/home/lz.txt"));
        outputStream.writeUTF("hello word");
        outputStream.flush();
        outputStream.close();
    }