public class Solution {
    public static boolean isIPv4Address(String inputString) {
        String[] a = inputString.split("\\.", -1);

        for (String v : a) {
            if (v.isEmpty() || v.length() > 3 || !v.matches("\\d+")) {
                return false;
            }
            int num = Integer.parseInt(v);
            if (num > 255 || !String.valueOf(num).equals(v)) {
                return false;
            }
        }

        return a.length == 4;
    }
}