hexStringToBytes/bytesToHexString

IccUtils.java

android/frameworks/opt/telephony/src/java/com/android/internal/telephony/uicc/IccUtils.java

static int
hexCharToInt(char c) {
	if (c >= '0' && c <= '9') return (c - '0');
	if (c >= 'A' && c <= 'F') return (c - 'A' + 10);
	if (c >= 'a' && c <= 'f') return (c - 'a' + 10);

	throw new RuntimeException ("invalid hex char '" + c + "'");
}

/**
 * Converts a hex String to a byte array.
 *
 * @param s A string of hexadecimal characters, must be an even number of
 *          chars long
 *
 * @return byte array representation
 *
 * @throws RuntimeException on invalid format
 */
public static byte[]
hexStringToBytes(String s) {
	byte[] ret;

	if (s == null) return null;

	int sz = s.length();

	ret = new byte[sz/2];

	for (int i=0 ; i <sz ; i+=2) {
		ret[i/2] = (byte) ((hexCharToInt(s.charAt(i)) << 4)
				| hexCharToInt(s.charAt(i+1)));
	}

	return ret;
}


/**
 * Converts a byte array into a String of hexadecimal characters.
 *
 * @param bytes an array of bytes
 *
 * @return hex string representation of bytes array
 */
public static String
bytesToHexString(byte[] bytes) {
	if (bytes == null) return null;

	StringBuilder ret = new StringBuilder(2*bytes.length);

	for (int i = 0 ; i < bytes.length ; i++) {
		int b;

		b = 0x0f & (bytes[i] >> 4);

		ret.append("0123456789abcdef".charAt(b));

		b = 0x0f & bytes[i];

		ret.append("0123456789abcdef".charAt(b));
	}

	return ret.toString();
}