It is common and simple files server which must work in all your java projects if you have internet access and know destination url

FilesSaver

public class FilesSaver {
    protected static String absolutePath;

    public static void setAbsolutePath(String absolutePath) {
        FilesSaver.absolutePath = absolutePath;
    }

    public static String constructPath(String relationPath) {
        while (relationPath.matches("^/.*$")) {
            relationPath = relationPath.replaceFirst("/", "");
        }
        return String.format(
                "%s/%s",
                absolutePath,
                relationPath
        );
    }

    public static File getFile(String relationPath) {
        File result = new File(constructPath(relationPath));
        if (!result.exists()) {
            return null;
        }
        return result;
    }

    public static void downloadFile(URL whereFrom, String relationPathToSave, Boolean overwrite) {
        File result = new File(constructPath(relationPathToSave));
        Boolean completeLoad = result.exists() && !overwrite;
        try {
            if (!completeLoad) {
                completeLoad = false;
                result = createFile(relationPathToSave);
                InputStream is = (InputStream)whereFrom.getContent();
                FileOutputStream fileOutputStream = new FileOutputStream(result);
                int read = -1;
                while ((read = is.read()) != -1) {
                    fileOutputStream.write(read);
                }
                is.close();
                fileOutputStream.flush();
                fileOutputStream.close();
                completeLoad = true;
            }
        } catch (IOException e) {
            System.err.println("E\\" + FilesSaver.class.getSimpleName() + ": Can't get content using url: " + whereFrom.toString());
            e.printStackTrace();
        } catch (NullPointerException e) {
            System.err.println("E\\" + FilesSaver.class.getSimpleName() + ": Object must be init");
            e.printStackTrace();
        } finally {
            if (!completeLoad && result.exists()) {
                result.delete();
            }
        }
    }

    public static File getOrDownload(URL whereFrom, String relationPath, Boolean overwrite) {
        File result = getFile(relationPath);
        if (result == null) {
            downloadFile(whereFrom, relationPath, overwrite);
            result = getFile(relationPath);
        }
        return result;
    }

    public static File getOrDownload(URL whereFrom, Boolean overwrite) {
        String relationPath = whereFrom.getPath();
        File result = getFile(relationPath);
        if (result == null) {
            downloadFile(whereFrom, relationPath, overwrite);
            result = getFile(relationPath);
        }
        return result;
    }

    public static Uri getUriOrDownload(String what, Boolean overwrite) {
        return Uri.fromFile(getOrDownload(what, overwrite));
    }

    public static Uri getFileUri(String relationPath) {
        return new Uri.Builder().appendPath(constructPath(relationPath)).build();
    }

    public static File createFile(String relationFilePath) {
        String fullPath = constructPath(relationFilePath);
        File result = new File(fullPath);
        String fileName = result.getName();
        result = new File(fullPath.replace(fileName, ""));
        result.mkdirs();
        result = new File(fullPath);
        try {
            result.createNewFile();
        } catch (IOException e) {
            e.printStackTrace();
            return null;
        }
        return result;
    }
}