How to validate an email address format in Java

Problem Description

How to validate an email address format?

Solution

Following example demonstrates how to validate e-mail address using matches() method of String class.

public class Main {
   public static void main(String[] args) {
      String EMAIL_REGEX = "^[\\w-_\\.+]*[\\w-_\\.]\\@([\\w]+\\.)+[\\w]+[\\w]$";
      String email1 = "user@domain.com";
      Boolean b = email1.matches(EMAIL_REGEX);
      System.out.println("is e-mail: "+email1+" :Valid = " + b);
      String email2 = "user^domain.co.in";
      b = email2.matches(EMAIL_REGEX);
      System.out.println("is e-mail: "+email2+" :Valid = " + b);
   }
}

Result

The above code sample will produce the following result.

is e-mail: user@domain.com :Valid = true
is e-mail: user^domain.co.in :Valid = false

The following is an example to validate an email address format.

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

public class Main {
   public static void main(String args[]) {
      List emails = new ArrayList();
      emails.add("sairamkrishna@tutorialspoint.com");
      emails.add("kittuprasad700@gmail.com");
      emails.add("sairamkrishna_mammahe%google-india.com");
      emails.add("sairam.krishna@gmail-indai.com");
      emails.add("sai#@youtube.co.in");
      emails.add("kittu@domaincom");
      emails.add("kittu#gmail.com");
      emails.add("@pindom.com");
      
      String regex = "^(.+)@(.+)$";
      Pattern pattern = Pattern.compile(regex);
      
      for (Object email : emails) {
         Matcher matcher = pattern.matcher((CharSequence) email);
         System.out.println(email + " : " + matcher.matches());
      } 
   }
}

The above code sample will produce the following result.

sairamkrishna@tutorialspoint.com : true
kittuprasad700@gmail.com : true
sairamkrishna_mammahe%google-india.com : false
sairam.krishna@gmail-indai.com : true
sai#@youtube.co.in : true
kittu@domaincom : true
kittu#gmail.com : false
@pindom.com : false