def hexStringToByteArray(s : String) = {
val len = s.length();
var data = new Array[Byte](len / 2)
var i = 0
while (i < len) {
val b = (Character.digit(s.charAt(i), 16) << 4) +
(Character.digit(s.charAt(i+1), 16))
data(i / 2) = b.asInstanceOf[Byte]
i+=2
}
data
}
Friday, November 30, 2012
Converting a Hex String to a Byte Array in Scala
Here's a Scala method that converts a hex string to an array of bytes. This is useful when needing to encrypt a hex string, because most of the crypto libraries operate on byte arrays.
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Asserted hex strings always have an even length, the conversion could be written without mutable data:
ReplyDeletedef hexStringToByteArray(s: String) = s.grouped(2).map(cc => (Character.digit(cc(0),16) << 4 | Character.digit(cc(1),16)).toByte).toArray
I assume, there are many things which can be improved. It depends on the context and the restrictions where the method is to be used.
Kind regards JP
An eternity late... How about this?
ReplyDelete// Group the string into hex pairs, parse hex values into integer, convert integer to byte.
s.grouped(2).toArray map { Integer.parseInt(_, 16).toByte }