ОС Лаб 2: File System Scanning

import java.io.*;
import java.util.HashSet;
import java.util.Objects;
import java.util.concurrent.locks.Lock;
import java.util.concurrent.locks.ReentrantLock;

public class FileScanner extends Thread {

    private final String fileToScan;


    //TODO: Initialize the start value of the counter
    private static Long counter = 0L;
    public static Lock lock = new ReentrantLock();

    public FileScanner(String fileToScan) {
        this.fileToScan = fileToScan;
        //TODO: Increment the counter on every creation of FileScanner object
        try {
            lock.lock();
            counter++;
        } finally {
            lock.unlock();
        }
    }

    public static void printInfo(File file) {

        //TODO: Print the info for the @argument File file, according to the requirement of the task
        if (file.isDirectory())
            System.out.printf("dir: %s %d\n", file.getName(), Objects.requireNonNull(file.listFiles()).length);
        else
            System.out.printf("file: %s %d\n", file.getName(), file.length());
    }

    public static Long getCounter() {
        return counter;
    }


    public void run() {

        //TODO Create object File with the absolute path fileToScan.
        File file;
        file = new File(this.fileToScan);

        //TODO Create a list of all the files that are in the directory file.
        File[] files;
        files = file.listFiles();

        // Test test
        HashSet<Thread> newThreads = new HashSet<>();

        for (File f : files) {

            /*
             * TODO If the File f is not a directory, print its info using the function printInfo(f)
             * */
            if (!f.isDirectory()) {
                printInfo(f);
            }

            /*
             * TODO If the File f is a directory, create a thread from type FileScanner and start it.
             * */
            if (f.isDirectory()) {
                printInfo(f);
                FileScanner newFileScanner;
                newFileScanner = new FileScanner(f.getAbsolutePath());
                newFileScanner.start();
                newThreads.add(newFileScanner);
            }


            //TODO: wait for all the FileScanner-s to finish
        }

        for (Thread thread : newThreads) {
            try {
                thread.join();
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
        }

    }

    public static void main(String[] args) throws InterruptedException {

        String FILE_TO_SCAN = "C:\\Users\\Hristijan\\Desktop\\Parent";

        //TODO Construct a FileScanner object with the fileToScan = FILE_TO_SCAN
        FileScanner fileScanner;
        fileScanner = new FileScanner(FILE_TO_SCAN);

        //TODO Start the thread from type FileScanner
        long startTime = System.nanoTime();
        fileScanner.start();
        //TODO wait for the fileScanner to finish
        fileScanner.join();
        long endTime = System.nanoTime();
        //TODO print a message that displays the number of thread that were created
        System.out.println(getCounter());

        System.out.printf("Time of job completion: %fs", (endTime - startTime) * 0.000000001);
    }

}