public static final String getASCIIHexStr(byte[] bs, int index, int len) {
		StringBuffer ascii = new StringBuffer();
		if ((bs == null) || (index > bs.length) || (index < 0) || (len <= 0) || (index + len > bs.length)) {
			return ascii.toString();
		}
		for (int i = 0; i < len; i++) {
			ascii.append((char) Integer.parseInt(String.valueOf(bs[(i + index)]), 16));
		}
		return ascii.toString();
	}