Added possibility to decode HEX strings without separator

Change-Id: I6e11ad2a3dc4e39b148a740d5f19d80705f78b48
(cherry picked from commit 6eaa33ab)

@@ -109,7 +109,25 @@ public final class HexString {
      * @throws NumberFormatException if input hex string cannot be parsed
      */
     public static byte[] fromHexString(final String values) {
-        String[] octets = values.split(":");
+        return fromHexString(values, ":");
+    }
+
+    /**
+     * Convert a hex-string with arbitrary separator to byte array.
+     * If separator is the empty string or null, then no separator will be considered.
+     *
+     * @param values hex string to be converted
+     * @return converted byte array
+     * @throws NumberFormatException if input hex string cannot be parsed
+     */
+    public static byte[] fromHexString(final String values, String separator) {
+        String regexSeparator;
+        if (separator == null || separator.length() == 0) {
+            regexSeparator = "(?<=\\G.{2})"; // Split string into several two character strings
+        } else {
+            regexSeparator = separator;
+        }
+        String[] octets = values.split(regexSeparator);
         byte[] ret = new byte[octets.length];
 
         for (int i = 0; i < octets.length; i++) {

@@ -21,6 +21,9 @@ import com.esotericsoftware.minlog.Log;
 
 import junit.framework.TestCase;
 
+import java.nio.ByteBuffer;
+import java.util.Arrays;
+
 import static org.junit.Assert.fail;
 
 /**
@@ -55,6 +58,22 @@ public class HexStringTest {
     }
 
     @Test
+    public void testFromHexString() {
+        String dpidStr = "3e:1f:01:fc:72:8c:63:31";
+        String dpidStrNoSep = "3e1f01fc728c6331";
+        long valid = 0x3e1f01fc728c6331L;
+        byte[] validBytes = ByteBuffer.allocate(Long.BYTES).putLong(valid).array();
+        byte[] testBytes = HexString.fromHexString(dpidStr);
+        byte[] testBytesNoSep = HexString.fromHexString(dpidStrNoSep, null);
+        byte[] testBytesUCase = HexString.fromHexString(dpidStr.toUpperCase());
+        byte[] testBytesUCaseNoSep = HexString.fromHexString(dpidStrNoSep.toUpperCase(), null);
+        TestCase.assertTrue(Arrays.equals(validBytes, testBytes));
+        TestCase.assertTrue(Arrays.equals(validBytes, testBytesNoSep));
+        TestCase.assertTrue(Arrays.equals(validBytes, testBytesUCase));
+        TestCase.assertTrue(Arrays.equals(validBytes, testBytesUCaseNoSep));
+    }
+
+    @Test
     public void testToLongError() {
         String dpidStr = "09:08:07:06:05:04:03:02:01";
         try {