Just something I had to figure out today. Thought I might post it, someone might find use for it. I had to validate ip addresses in an android app I am helping build. Below is the method I used for the validation. The same method will work a java application as well.
public static boolean isIpAddress(String ipAddress) { String IPADDRESS_PATTERN = "^([01]?\\d\\d?|2[0-4]\\d|25[0-5])\\." + "([01]?\\d\\d?|2[0-4]\\d|25[0-5])\\." + "([01]?\\d\\d?|2[0-4]\\d|25[0-5])\\." + "([01]?\\d\\d?|2[0-4]\\d|25[0-5])$"; Pattern pattern = Pattern.compile(IPADDRESS_PATTERN); Matcher matcher = pattern.matcher(ipAddress); return matcher.matches(); }