Downloader

import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.net.MalformedURLException;
import java.net.URL;
import java.nio.file.Files;
import java.nio.file.Paths;


public class Downloader {
    private URL url;
    private byte[] buffer;

    public Downloader(String url)
    {
        try {
            this.url = new URL(url);
        } catch (MalformedURLException e) {
            e.printStackTrace();
        }
    }

    public void download() throws IOException
    {
        if (this.url == null)
            return;

        DataInputStream is = null;
        DataOutputStream os = null;
        try {
            // TODO pouzijte promennou url a ziskejte z ni InputStream OK
            // TODO pouzijte Buffer OK
            is = new DataInputStream(url.openStream());
            buffer = new byte[1024*1024];
            int length = 0;

            // TODO z promenne url ziskejte jmeno souboru OK
            // TODO jmeno souboru je vcetne cesty. Orezte dany string a ziskejte pouze jmeno s priponou OK
            String fileName = url.getPath();
            fileName = fileName.replace("/", "");
            //System.out.println(fileName);

            // TODO vytvorte soubor s nazvem z promenne fileName OK
            // TODO pouzijte Buffer
            File file = new File(fileName);
            os = new DataOutputStream(new FileOutputStream(file));


            int c;
            // TODO zapiste vsechna data z is do os. Pouzijte promennou c OK
//          while ((c = is.read()) != -1) {
//              os.write(c);
//          }

            while ((length = is.read(buffer)) >= 0){
                os.write(buffer, 0, length);
            }


        }

        // TODO doplnte block finally kde oba streamy zavrete pokud nejsou null
        finally
        {
            if (os != null) os.close();
            if (is != null) is.close();
        }
    }
}