Java Program to Validate Phone Numbers using Google’s libphonenumber Library

Validating phone numbers is a common prerequisite in today’s web, mobile, or desktop applications, but Java does not have an integrated method for carrying out this kind of common validation. So, we have to use some open source libraries to perform such validation. One such library is Google’s phone number library. It helps to verify any phone number, whether foreign, specific to India, or specific to any country.

We can also use regular expressions to validate the phone numbers, but it requires some skills to write such complex expressions and then the testing would be an endless task.

The libphonenumber is an open-source library from Google for formatting, parsing, and validating international phone numbers. It contains many methods to achieve such functionality. Some of them are discussed below:

Return Type	Method	Description
String	format(Phonenumber.PhoneNumber number, PhoneNumberUtil.PhoneNumberFormat numberFormat)	Uses the default rules to format a phone number in the format specified.
String	formatNumberForMobileDialing(Phonenumber.PhoneNumber number, java.lang.String regionCallingFrom, boolean withFormatting)	Returns the number in a formatted string such that it can be dialed from a cell phone in that region.
boolean	isMobileNumberPortableRegion(java.lang.String regionCode)	If the region passed as an argument supports mobile number portability, the method returns true.
boolean	isNumberMatch(Phonenumber.PhoneNumber firstNumberIn, Phonenumber.PhoneNumber secondNumberIn)	It takes two phone number and checks them for equality
boolean	isPossibleNumber(java.lang.CharSequence number, java.lang.String regionDialingFrom)	Verify that a telephone number is a possible number given in the form of a string and the region from which the number can be dialed.
boolean	isValidNumberForRegion(Phonenumber.PhoneNumber number, java.lang.String regionCode)	Checks whether the given number is valid for a particular region
boolean	isValidNumber(Phonenumber.PhoneNumber number)	Validates whether a phone number matches a specific pattern
boolean	canBeInternationallyDialled(Phonenumber.PhoneNumber number)	Returns true in case the number can be dialed from outside the specified region
int	getCountryCodeForRegion(java.lang.String regionCode)	Returns the country calling code for a specific region
PhoneNumberUtil.PhoneNumberType	getNumberType(Phonenumber.PhoneNumber number)	This method returns the type of number based on the number itself. For example, Toll-Free, Mobile, FixedLine, etc.

 This is a rich library with even more utility features and takes care of much of the needs of our program.

Below is Java Implementation for Validating  Phone Numbers using Google’s libphonenumber Library. Here we will be using Eclipse IDE.

Step 1: Creating a Maven Project

To begin with first create a Maven Project in Eclipse. The reason behind creating a Maven Project rather than a normal Java Project is that the libphonenumber library is present in the Maven Repository so we have to use it as a dependency in our project.

Leave everything to be the default. The Artifact Id will be the name of your Maven project.

Step 2: Adding the Dependency

Once you have created the Maven Project, add the libphonenumber dependency in the pom.xml file. As soon as you save the file, the library will be downloaded for offline use.

XML

<project xmlns="http://maven.apache.org/POM/4.0.0"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
  <modelVersion>4.0.0</modelVersion>
  <groupId>com.Demo</groupId>
  <artifactId>DemoProject</artifactId>
  <version>0.0.1-SNAPSHOT</version>
  <dependencies>
      <dependency>
        <groupId>com.googlecode.libphonenumber</groupId>
        <artifactId>libphonenumber</artifactId>
        <version>8.12.16</version>
      </dependency>
  </dependencies>
</project>

Step 3: Creating the Driver Class

Now, simply create a Java class to use the functionalities of this library.

Java

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

public class GFG {

    public static void main(String args[])
    {
        // creating an array of random phone numbers
        String[] phonenumbers
            = { "+91 94483 76473", "1800 425 3800",
                "+91 83944 7484", "0294 2424447" };

        // iterating over each number to validate
        for (String phone : phonenumbers) {
            if (isPhoneNumberValid(phone)) {
                System.out.println(phone + " is valid.");
            }
            else {
                System.out.println(phone
                                   + " is not valid.");
            }
        }
    }

    // this method return true if the passed phone number is
    // valid as per the region specified
    public static boolean isPhoneNumberValid(String phone)
    {
        // creating an instance of PhoneNumber Utility class
        PhoneNumberUtil phoneUtil
            = PhoneNumberUtil.getInstance();

        // creating a variable of type PhoneNumber
        PhoneNumber phoneNumber = null;

        try {
            // the parse method parses the string and
            // returns a PhoneNumber in the format of
            // specified region
            phoneNumber = phoneUtil.parse(phone, "IN");

            // this statement prints the type of the phone
            // number
            System.out.println(
                "\nType: "
                + phoneUtil.getNumberType(phoneNumber));
        }
        catch (NumberParseException e) {

            // if the phoneUtil is unable to parse any phone
            // number an exception occurs and gets caught in
            // this block
            System.out.println(
                "Unable to parse the given phone number: "
                + phone);
            e.printStackTrace();
        }

        // return the boolean value of the validation
        // performed
        return phoneUtil.isValidNumber(phoneNumber);
    }
}

Output:

Type: MOBILE
+91 94483 76473 is valid.
Type: TOLL_FREE
1800 425 3800 is valid.
Type: UNKNOWN
+91 83944 7484 is not valid.
Type: FIXED_LINE
0294 2424447 is valid.