Validate IP Address using Java Regular Expression

Ip Address Validator Regular Expression Pattern

(?:(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\\.){3}(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)

Regular ExpressionDescription

for more regular expression syntax refer Java Regular Expression Syntax Descriptions

IpAddressValidator .java

package com.javatutorialcorner.regex;

import java.util.regex.Matcher;
import java.util.regex.Pattern;

public class IpAddressValidator {
 private static final String PATTERN = "(?:(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\\.){3}(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)";

 public static void main(String[] args) {

  System.out.println("Validate  192.1.1.1 "+validate("192.1.1.1"));
  System.out.println("Validate  192.10.10.10 "+validate("192.10.10.10"));
  System.out.println("Validate 192.100.100.100 "+validate("192.100.100.100"));
  System.out.println("Validate 255.255.255.255 "+validate("255.255.255.255"));
  System.out.println("Validate 255.255.255.256 "+validate("255.255.255.256"));
  System.out.println("Validate 255.255.256.255 "+validate("255.255.256.255"));
  System.out.println("Validate 255.256.255.255 "+validate("255.256.255.255"));
  System.out.println("Validate 256.255.255.255 "+validate("256.255.255.255"));
  System.out.println("Validate 25a.255.255.255 "+validate("256.255.255.255"));

 }

 private static boolean validate(String password) {
  Pattern pattern = Pattern.compile(PATTERN);
  Matcher matcher = pattern.matcher(password);
  return matcher.matches();

 }

}

Output :

Validate 192.1.1.1 trueValidate 192.10.10.10 trueValidate 192.100.100.100 trueValidate 255.255.255.255 trueValidate 255.255.255.256 falseValidate 255.255.256.255 falseValidate 255.256.255.255 falseValidate 256.255.255.255 falseValidate 25a.255.255.255 false