public void download(String f, File output) {
        try {
            System.out.println("Downloading " + f + " to " + output);
            URL file = new URL(f);
            File folder = output.getParentFile();
            if (!folder.exists())
                folder.mkdirs();
            if (output.exists())
                output.delete();
            output.createNewFile();
            byte[] buffer = new byte[1024];
            int len;
            BufferedInputStream bis = new BufferedInputStream(file.openStream());
            FileOutputStream fos = new FileOutputStream(output);
            while ((len = bis.read(buffer)) != -1)
                fos.write(buffer,0,len);
            bis.close();
            fos.flush();
            fos.close();
        } catch (Exception e) {
            System.out.println("Problem downloading " + f);
            e.printStackTrace();
        }
    }