Day-16 Validate IP Address

class Solution {
    public String validIPAddress(String IP) {
        
        String ipv4set="([0-9]|[1-9][0-9]|1[0-9][0-9]|2[0-4][0-9]|25[0-5])";
        String ipv4regex="^("+ipv4set+"\\.){3}"+ipv4set+"$";
        String ipv6set="([0-9a-fA-F]{1,4})";
        String ipv6regex="("+ipv6set+"\\:){7}"+ipv6set;
        
        if( IP.matches(ipv4regex) ){
            return "IPv4";
        }
        else if(IP.matches(ipv6regex)){
            return "IPv6";
        }
        else{
            return "Neither";
        }
    }
}

class Solution {
  public String validateIPv4(String IP) {
    String[] nums = IP.split("\\.", -1);
    for (String x : nums) {
      if (x.length() == 0 || x.length() > 3) return "Neither";
      if (x.charAt(0) == '0' && x.length() != 1) return "Neither";
      for (char ch : x.toCharArray()) {
        if (! Character.isDigit(ch)) return "Neither";
      }
      if (Integer.parseInt(x) > 255) return "Neither";
    }
    return "IPv4";
  }

  public String validateIPv6(String IP) {
    String[] nums = IP.split(":", -1);
    String hexdigits = "0123456789abcdefABCDEF";
    for (String x : nums) {
      if (x.length() == 0 || x.length() > 4) return "Neither";
      for (Character ch : x.toCharArray()) {
        if (hexdigits.indexOf(ch) == -1) return "Neither";
      }
    }
    return "IPv6";
  }

  public String validIPAddress(String IP) {
    if (IP.chars().filter(ch -> ch == '.').count() == 3) {
      return validateIPv4(IP);
    }
    else if (IP.chars().filter(ch -> ch == ':').count() == 7) {
      return validateIPv6(IP);
    }
    else return "Neither";
  }
}