Parsing an IP Address in Java

parseIpAddress.java

public static InetAddress parseIpAddress(String ip) throws IllegalArgumentException {
	StringTokenizer tok = new StringTokenizer(ip, ".");

	if (tok.countTokens() != 4) {
		throw new IllegalArgumentException("IP address must be in the format 'xxx.xxx.xxx.xxx'");
	}

	byte[] data = new byte[4];
	int i = 0;
	while (tok.hasMoreTokens()) {
		String strVal = tok.nextToken();
		try {
			int val = Integer.parseInt(tok.nextToken(), 10);

			if (val < 0 || val > 255) {
				throw new IllegalArgumentException("Illegal value '" + val + "' at byte " + (i + 1) + " in the IP address.");
			}

			data[i++] = (byte) Integer.parseInt(tok.nextToken(), 10);
		} catch (NumberFormatException e) {
			throw new IllegalArgumentException("Illegal value '" + strVal + "' at token " + (i + 1) + " in the IP address.", e);
		}
	}

	try {
		return InetAddress.getByAddress(ip, data);
	} catch (UnknownHostException e) {
		// This actually can't happen since the method InetAddress.getByAddress(String, byte[])
		// doesn't perform any lookups and we have already guaranteed that the length of data is 4
		throw new Error("UnknownHostException somehow thrown when creating an InetAddress", e);
	}
}

This code cannot possibly work: calling Integer.parseInt(tok.nextToken()) will advance to the next token, skipping the one it should be working on. Author obviously never tested this code.

inside while() loop, on lines 13 and 19, change tok.nextToken() to strVal