import java.io.*;

public class FileManager {

    public static void main(String[] args) {

        String from = "E:\\JAVA\\Luxoft Traning\\JVA-008\\Path2";
        String to = "E:\\JAVA\\Luxoft Traning\\JVA-008\\Path3";

        try {
            copy(from, to);
        } catch (IOException | NullPointerException e) {
            e.printStackTrace();
        }
    }

    public static void copy(String from, String to) throws IOException, NullPointerException {

        File source = new File(from);
        File destination = new File(to);

        InputStream inputStream;
        OutputStream outputStream;

        if (source.isFile()) {
            inputStream = new FileInputStream(source);
            outputStream = new FileOutputStream(destination);

            byte[] buffer = new byte[1024];
            int bufferSize;
            while ((bufferSize = inputStream.read(buffer)) > 0) {
                outputStream.write(buffer, 0, bufferSize);
            }
            inputStream.close();
            outputStream.close();

        } else {

            if (!destination.exists()) {
                destination.mkdir();
            }
            String files[] = source.list();

            for (String file : files) {
                File sourceFile = new File(source, file);
                File destinationFile = new File(destination, file);
                copy(sourceFile.getCanonicalPath(), destinationFile.getCanonicalPath());
            }
        }
    }
}