I want to split each of two chars in string and convert it to hex byte array representation, i am just lost how to do this.
in string a= hex a which is 10 in decimal in string b= hex b which is 11 in decimal
String toConvert = "abbbbbbbbbbbbbbbbbbbbbbc";
byte[] output = new byte[12];
Input
ab bb bb bb bb bb bb bb bb bb bb bc
output
[-85, -69, -69, -69, -69, -69, -69, -69, -69, -69, -69, -68]
Takes the first character in a group of two, multiplies its hex value by 16 (it's in the 161 place). That result is added to the second character's hex value.
String toConvert = "abbbbbbbbbbbbbbbbbbbbbbc";
byte[] output = new byte[toConvert.length() / 2];
for (int i = 0; i < output.length; i++) {
output[i] |= Character.digit(toConvert.charAt(i * 2), 16) * 16;
output[i] |= Character.digit(toConvert.charAt(i * 2 + 1), 16);
}
Apache Common Codec's Hex class does exactly what you need:
byte[] bytes = Hex.decodeHex("abbbbbbbbbbbbbbbbbbbbbbc".toCharArray());
If you can't/won't use third parties, you can always "borrow" their implementation (slightly simplified - I omitted correctness checks for simplicity):
public static byte[] decodeHex(final char[] data) {
final int len = data.length;
// Handle empty string - omitted for clarity's sake
final byte[] out = new byte[len >> 1];
// two characters form the hex value.
for (int i = 0, j = 0; j < len; i++) {
int f = Character.digit(data[j], 16) << 4;
j++;
f = f | Character.digit(data[j], 16);
j++;
out[i] = (byte) (f & 0xFF);
}
return out;
}
for(int i = 0; i < 12; i++) {
output[i] = (byte) Integer.parseInt(toConvert.substring(i*2, i*2+2), 16);
}
Integer.valueOf?
in string a= hex a which is 10 in decimal in string b= hex b which is 11 in decimalYou mean inString toConvert? What a terrible example! BetterString toConvert = "0344A7DF";. And you will not convert to hex but decode from hex representation.