public String getPiecesStr(){
        if(getPieces() == null){
            return null;
        }
        BASE64Decoder dec = new BASE64Decoder();
        try{
            byte[] b = dec.decodeBuffer(getPieces());
            StringBuilder sb = new StringBuilder();
            for(int i = 0; i < b.length; i++){
                sb.append(Integer.toBinaryString(b[i]));
            }
            return sb.toString();
        }catch(IOException e){
            return null;
        }
    }