java 짧은 URL 만들기

public static String getShortUrl()

{ 

ByteArrayOutputStream baos = new ByteArrayOutputStream();

        DataOutputStream dos = new DataOutputStream(baos);

        UUID uuid = UUID.randomUUID();

        String shortUrlKey = null;

        try 

        {

   dos.writeLong(uuid.getMostSignificantBits()); 

           String encoded = new String(Base64.encodeBase64(baos.toByteArray()), "ISO-8859-1");

           shortUrlKey = StringUtils.left(encoded, 5);

       

           String match = "[^\uAC00-\uD7A3xfe0-9a-zA-Z\\s]";

           shortUrlKey =shortUrlKey.replaceAll(match, Character.toString(((char)((Math.random() * 26) + 97)))  );

} 

        catch (IOException e) {

e.printStackTrace();

shortUrlKey = null;

        }

    return shortUrlKey;

}