How To Validate Phone Numbers in Java (Regular Expression + Google libphonenumber)

A quick guide to how to validate phone numbers in java for different countries such as the USA, IN. Example programs with Regular Expression and Google libphonenumber API.

1. Introduction

In this tutorial, We’ll learn how to validate phone numbers in java. This is to validate mainly the USA and India country phone numbers but after seeing the example you can develop the validation rules for other countries.

This is a common requirement to verify mobile numbers as we do validation for email address validation but java does not have built-in capability to provide such methods. But, We can achieve this with the help of regular expression and google api with libphonenumber.

Let us jump into writing example programs.

2. Regular Expression

Regular expression implementation is a bit tricky because phone number has lots of formats with different extensions.

For example, here are some of the common ways of writing phone numbers for the
USA.

1234567890
123-456-7890
123-456-7890 x1234
123-456-7890 ext1234
(123)-456-7890
123.456.7890
123 456 7890

India:

9123124123

Phone Number Validation with Regular Expression

package com.java.w3schools.blog.java.program.to.libphonenumber;

 

public class PhoneValidationRegularExpression {

 

 public static void main(String[] args) {

 

  System.out.println("Validation for 1234567890 : " + validatePhoneNumber("1234567890"));

  System.out.println("Validation for 1234 567 890 : " + validatePhoneNumber("1234 567 890")); 

  System.out.println("Validation for 123 456 7890 : " + validatePhoneNumber("123 456 7890"));

  System.out.println("Validation for 123-567-8905 : " + validatePhoneNumber("123-567-8905"));

  System.out.println("Validation for 9866767545 : " + validatePhoneNumber("9866767545"));

  System.out.println("Validation for 123-456-7890 ext9876 : " + validatePhoneNumber("123-456-7890 ext9876"));

 

 }

 

 private static boolean validatePhoneNumber(String phoneNumber) {

  // validate phone numbers of format "1234567890"

  if (phoneNumber.matches("\\d{10}"))

   return true;

  // validating phone number with -, . or spaces

  else if (phoneNumber.matches("\\d{3}[-\\.\\s]\\d{3}[-\\.\\s]\\d{4}"))

   return true;

  // validating phone number with extension length from 3 to 5

  else if (phoneNumber.matches("\\d{3}-\\d{3}-\\d{4}\\s(x|(ext))\\d{3,5}"))

   return true;

  // validating phone number where area code is in braces ()

  else if (phoneNumber.matches("\\(\\d{3}\\)-\\d{3}-\\d{4}"))

   return true;

  // Validation for India numbers

  else if (phoneNumber.matches("\\d{4}[-\\.\\s]\\d{3}[-\\.\\s]\\d{3}"))

   return true;

  else if (phoneNumber.matches("\\(\\d{5}\\)-\\d{3}-\\d{3}"))

   return true;

 

  else if (phoneNumber.matches("\\(\\d{4}\\)-\\d{3}-\\d{3}"))

   return true;

  // return false if nothing matches the input

  else

   return false;

 

 }

}

Output:

Validation for 1234567890 : true

Validation for 1234 567 890 : true

Validation for 123 456 7890 : true

Validation for 123-567-8905 : true

Validation for 9866767545 : true

Validation for 123-456-7890 ext9876 : true

3. Google libphonenumber Example

If you go with the regex approach, you need to do lots of testing to cover all the corner cases. But, if we have some api that provides this functionality with proper testing that would be good to use in our application.

libphonenumber API is provided by Google as an opensource library that provides the functionalities such as parsing, formatting, validating and storing international phone numbers.

This API is optimized for running on smartphones and also used by the Android framework.

The main advantage of this API is that you can format or validate and parse any country or region mobile numbers.

Class PhoneNumberUtil is a utility for international phone numbers. Functionality includes formatting, parsing, and validation.

package com.java.w3schools.blog.java.program.to.libphonenumber;

 

import com.google.i18n.phonenumbers.NumberParseException;

import com.google.i18n.phonenumbers.PhoneNumberUtil;

import com.google.i18n.phonenumbers.Phonenumber;

import com.google.i18n.phonenumbers.Phonenumber.PhoneNumber;

 

public class PhoneValidationWIthGooglelibphonenumberAPI {

 

 public static void main(String[] args) throws NumberParseException {

 

  PhoneNumberUtil numberUtil = PhoneNumberUtil.getInstance();

 

  PhoneNumber phoneNumber = numberUtil.parse("9866123456", "IN");

 

  boolean isValid = numberUtil.isValidNumber(phoneNumber);

 

  System.out.println("Checking given phone number is vaid : " + isValid);

 }

 

}

Output:

Checking given phone number is vaid : true

Another Example To Validate USA OR India Phone numbers:

Sample phone numbers

package com.java.w3schools.blog.java.program.to.libphonenumber;

 

import com.google.i18n.phonenumbers.NumberParseException;

import com.google.i18n.phonenumbers.PhoneNumberUtil;

import com.google.i18n.phonenumbers.Phonenumber.PhoneNumber;

 

public class PhoneValidationWIthGooglelibphonenumberAPI {

 

 public static void main(String[] args) throws NumberParseException {

 

  System.out.println("USA phone number validations: ");

  String[] usPhoneNumbers = { "(541) 754-3010", "+1-541-754-3010", "1-541-754-3010", "001-541-754-3010",

    "191 541 754 3010" };

  validatePhoneNumber(usPhoneNumbers, "US");

 

  System.out.println("\nindia phone number validations: ");

  String[] indiaPhoneNumbers = { "+91 7503907302", "9702522865", "+91–8477812345", "+91 9999999999",

    "+91 9688 123 456", "+9688 123 456" };

  validatePhoneNumber(indiaPhoneNumbers, "IN");

 

 }

 

 private static void validatePhoneNumber(String[] phoneNumbers, String region) throws NumberParseException {

 

  PhoneNumberUtil numberUtil = PhoneNumberUtil.getInstance();

 

  for (String number : phoneNumbers) {

 

   PhoneNumber phoneNumber = numberUtil.parse(number, region);

 

   boolean isValid = numberUtil.isValidNumber(phoneNumber);

 

   if (isValid) {

    System.out.println(number + " is a valid number.");

   } else {

    System.out.println(number + " is a not valid number.");

   }

 

  }

 

 }

}

Output:

USA phone number validations: 

(541) 754-3010 is a valid number.

+1-541-754-3010 is a valid number.

1-541-754-3010 is a valid number.

001-541-754-3010 is a not valid number.

191 541 754 3010 is a not valid number.

 

india phone number validations: 

+91 7503907302 is a valid number.

9702522865 is a valid number.

+91–8477812345 is a valid number.

+91 9999999999 is a valid number.

+91 9688 123 456 is a valid number.

+9688 123 456 is a not valid number.

PhoneNumberUtil API

4. PhoneNumberType

This api supports all the below types of numbers.

FIXED_LINE  

FIXED_LINE_OR_MOBILE  

MOBILE  

PAGER  

PERSONAL_NUMBER  

PREMIUM_RATE  

SHARED_COST  

TOLL_FREE  

UAN  

UNKNOWN  

VOICEMAIL  

VOIP

PhoneNumberUtil.PhoneNumberType