Add `HexUtils`

src/java/iced-x86/src/test/java/com/github/icedland/iced/x86/HexUtils.java

@@ -0,0 +1,51 @@
+// SPDX-License-Identifier: MIT
+// Copyright (C) 2018-present iced project and contributors
+
+package com.github.icedland.iced.x86;
+
+public final class HexUtils {
+	public static byte[] toByteArray(String hexData) {
+		if (hexData == null)
+			throw new NullPointerException();
+		if (hexData.length() == 0)
+			return new byte[0];
+		int len = 0;
+		for (int i = 0; i < hexData.length(); i++) {
+			if (hexData.charAt(i) != ' ')
+				len++;
+		}
+		byte[] data = new byte[len / 2];
+		int w = 0;
+		for (int i = 0; ;) {
+			while (i < hexData.length() && Character.isWhitespace(hexData.charAt(i)))
+				i++;
+			if (i >= hexData.length())
+				break;
+			int hi = tryParseHexChar(hexData.charAt(i++));
+			if (hi < 0)
+				throw new UnsupportedOperationException();
+
+			while (i < hexData.length() && Character.isWhitespace(hexData.charAt(i)))
+				i++;
+			if (i >= hexData.length())
+				throw new UnsupportedOperationException();
+			int lo = tryParseHexChar(hexData.charAt(i++));
+			if (lo < 0)
+				throw new UnsupportedOperationException();
+			data[w++] = (byte)((hi << 4) | lo);
+		}
+		if (w != data.length)
+			throw new UnsupportedOperationException();
+		return data;
+	}
+
+	private static int tryParseHexChar(char c) {
+		if ('0' <= c && c <= '9')
+			return c - '0';
+		if ('A' <= c && c <= 'F')
+			return c - 'A' + 10;
+		if ('a' <= c && c <= 'f')
+			return c - 'a' + 10;
+		return -1;
+	}
+}