Salut j'ai utiliser ca et ca marche bien

public static int bytestoInt(int nb) throws IOException {

		byte[] bytes = new byte[nb];
		inputS.read(bytes);

		if (bytes == null) {
			return 0;
		}


		StringBuffer hashString = new StringBuffer();

		for (int i = 0; i < bytes.length; ++i) {
			String hex = encodeHex(Integer.toHexString(bytes[i]));

			if (hex.length() == 1) {
				hashString.append(hex.charAt(hex.length() - 1));
			} else {
				hashString.append(hex.substring(hex.length() - 2));
			}
		}

		// return hashString.toString().toUpperCase();
		return Integer.parseInt((hashString.toString()), 16);
	}