Taken into account PR review comments

Author: thboileau

org.restlet.java/org.restlet/src/main/java/org/restlet/data/Reference.java

@@ -2882,7 +2882,7 @@ private void validateAuthority(String authority) {
 			if (ipV6EndIndex == -1) {
 				throw new IllegalArgumentException("Invalid IPv6 address format: no closing bracket");
 			} else {
-				validateIPv6(authority.substring(0, ipV6EndIndex + 1));
+				validateIpV6(authority.substring(0, ipV6EndIndex + 1));
 				if (ipV6EndIndex + 1 < authority.length()) {
 					if (authority.charAt(ipV6EndIndex + 1) == ':') {
 						validateHostPort(authority.substring(ipV6EndIndex + 2));
@@ -2916,56 +2916,65 @@ private void validateHostPort(final String hostPort) {
     /**
      * Validate an IP v6 according to RFC 2373.
      * 
-     * @param ipv6 The IP v6 to validate.
+     * @param ipV6 The IP v6 to validate.
      */
-	private void validateIPv6(String ipv6) {
-		if (ipv6 == null || ipv6.isEmpty()) {
+	private void validateIpV6(String ipV6) {
+		if (ipV6 == null || ipV6.isEmpty()) {
 			throw new IllegalArgumentException("Invalid IPv6 address");
 		}
 
-		if (ipv6.startsWith("[")) {
-			ipv6 = ipv6.substring(1);
-		}
-		if (ipv6.endsWith("]")) {
-			ipv6 = ipv6.substring(0, ipv6.length() - 1);
-		}
+		ipV6 = trimIpV6Brackets(ipV6);
 
 		// Check for double colon compression (only one allowed)
 		int doubleColonCount = 0;
-		int idx = ipv6.indexOf("::");
+		int idx = ipV6.indexOf("::");
 		while (idx != -1) {
 			doubleColonCount++;
-			idx = ipv6.indexOf("::", idx + 2);
+			idx = ipV6.indexOf("::", idx + 2);
 		}
 		if (doubleColonCount > 1) {
 			throw new IllegalArgumentException("Invalid IPv6 address format");
 		}
 
-		String[] parts = ipv6.split(":", -1);
+		String[] parts = ipV6.split(":", -1);
 		int maxParts = 8;
 
 		if (parts.length > maxParts) {
 			throw new IllegalArgumentException("Invalid IPv6 address format");
 		}
 
 		for (String part : parts) {
-			if (part.isEmpty() && doubleColonCount == 0) {
+			validateIpV6Part(part, doubleColonCount);
+		}
+	}
+
+	private void validateIpV6Part(final String part, final int doubleColonCount) {
+		if (part.isEmpty() && doubleColonCount == 0) {
+			throw new IllegalArgumentException("Invalid IPv6 address format");
+		}
+		if (!part.isEmpty()) {
+			if (part.length() > 4) {
 				throw new IllegalArgumentException("Invalid IPv6 address format");
 			}
-			if (!part.isEmpty()) {
-				if (part.length() > 4) {
+			for (char c : part.toCharArray()) {
+				if (!isAlpha(c) && !isDigit(c)) {
 					throw new IllegalArgumentException("Invalid IPv6 address format");
 				}
-				for (char c : part.toCharArray()) {
-					if (!isAlpha(c) && !isDigit(c)) {
-						throw new IllegalArgumentException("Invalid IPv6 address format");
-					}
-				}
 			}
 		}
 	}
 
-    /**
+	private String trimIpV6Brackets(String ipV6) {
+		if (ipV6.startsWith("[")) {
+			ipV6 = ipV6.substring(1);
+		}
+		if (ipV6.endsWith("]")) {
+			ipV6 = ipV6.substring(0, ipV6.length() - 1);
+		}
+		return ipV6;
+	}
+
+	/**
      * Validate a scheme according to RFC 3986.
      * 
      * @param scheme The scheme to validate.