2021 10 8

jva操作hsfs:

public static void download(FileSystem fs,String hadooppath,String name)
{
    try {
        File file = new File("D:\\+name");

        String newpath=null;
        if (!file.exists()) {
            newpath="hadoop_"+name;
            System.out.println("本地文件存在，另存文件名："+newpath);
            InputStream input = null;
            OutputStream output = null;
            input = fs.open(new Path(hadooppath));
            output = new FileOutputStream("D:\\"+newpath);
            IOUtils.copyBytes(input, output, 4096, true);
        }else{
            fs.copyToLocalFile(false, new Path("/user/hadoop/text/sean.txt"), new Path("E:/"), true);
        }
        fs.close();
    } catch (IOException e) {
        e.printStackTrace();
    }
}

public static void printtext(FileSystem fs, String hadooppath) {
    Path remotePath = new Path(hadooppath);
    FSDataInputStream in = null;
    try {
        in = fs.open(remotePath);
        BufferedReader d = new BufferedReader(new InputStreamReader(in));
        String line = null;
        while ((line = d.readLine()) != null) {
            String[] strarray = line.split(" ");
            for (int i = 0; i < strarray.length; i++) {
                System.out.print(strarray[i]);
                System.out.print(" ");

            }

            System.out.println(" ");
        }
    } catch (IOException e) {
        e.printStackTrace();
    }
}