2021 10 11

java操作hdfs:

 

public static void deletedir(FileSystem fs,String dir)
{
    Path hadooppath = new Path(dir);
    try {
        if (!fs.exists(hadooppath)){
            System.out.println("目录不存在！");
        }else{
            FileStatus[] filelist = fs.listStatus(new Path(dir));
            if(filelist.length==0)
            {
                fs.delete(hadooppath,true);
            }else{
                System.out.println("目录非空，是否删除：1、是 2、否");
                int a=cin.nextInt();
                if(a==1)  fs.delete(hadooppath,true);
            }
        }
    } catch (IOException e) {
        e.printStackTrace();
    }

}
public static void addtext(FileSystem fs, String hadooppath) {
    Path remotePath = new Path(hadooppath);
    FSDataInputStream in = null;
    try {
        if(fs.exists(remotePath)) {
            in = fs.open(remotePath);
            BufferedReader d = new BufferedReader(new InputStreamReader(in));
            String line = null;
            System.out.println("文件内容：");
            String text="";
            String addtext="";
            while ((line = d.readLine()) != null) {
                String[] strarray = line.split(" ");
                for (int i = 0; i < strarray.length; i++) {
                    text+=strarray[i];
                    System.out.print(strarray[i]);
                    System.out.print(" ");
                }
                System.out.println(" ");
            }
            System.out.println("输入追加内容:");
            addtext=cin.next();
            int temp=0;
            System.out.println("追加到原有文件的开头或结尾：1、开头 2、末尾");
            temp=cin.nextInt();
            if(temp==1)
            {
               text=addtext+text;
            }else{
                text+=addtext;
            }
            FSDataOutputStream os = fs.create(remotePath);
            os.writeUTF(text);
            os.close();
            d.close();
        }else{
            System.out.println("文件不存在！");
        }
    } catch (IOException e) {
        e.printStackTrace();
    }
}
public static void movefile(FileSystem fs,String path,String newPath)
{
    try {
        if (fs.exists(new Path(newPath))&&fs.exists(new Path(path))){
            fs.rename(new Path(path),new Path(newPath));
        }else {
            System.out.println("路径错误！");
        }
    } catch (Exception e) {

    } finally {
        //close(fs);
    }
}