Syntax error Java regular expression program to validate an email including blank field valid as well

Java regular expression program to validate an email including blank field valid as well

Following regular expression matches given e-mail id including the blank input −

^([a-zA-Z0-9._%+-]+@[a-zA-Z0-9.-]+\.[a-zA-Z]{2,6})?$

Where,

  • ^ matches the starting of the sentence.

  • [a-zA-Z0-9._%+-] matches one character from English alphabet (both cases), digits, "+", "_", ".","" and, "-" before the @ symbol.

  • + indicates the repetition of the above mentioned set of characters one or more times.

  • @ matches itself

  • [a-zA-Z0-9.-] matches one character from English alphabet (both cases), digits, "." and "-" after the @ symbol

  • \.[a-zA-Z]{2,6} two to 6 letter for email domain after "."

  • $ indicates the end of the sentence

Example 1

 Live Demo

import java.util.Scanner;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
public class SampleTest {
   public static void main( String args[] ) {
      String regex = "^([a-zA-Z0-9._%+-]+@[a-zA-Z0-9.-]+\.[a-zA-Z]{2,6})?$";
      //Reading input from user
      Scanner sc = new Scanner(System.in);
      System.out.println("Enter your name: ");
      String name = sc.nextLine();
      System.out.println("Enter your e-mail: ");
      String e_mail = sc.nextLine();
      System.out.println("Enter your age: ");
      int age = sc.nextInt();
      //Instantiating the Pattern class
      Pattern pattern = Pattern.compile(regex);
      //Instantiating the Matcher class
      Matcher matcher = pattern.matcher(e_mail);
      //verifying whether a match occurred
      if(matcher.find()) {
         System.out.println("e-mail value accepted");
      } else {
         System.out.println("e-mail not value accepted");
      }
   }
}

Output1

Enter your name:
krishna
Enter your e-mail:
Enter your age:
20
e-mail value accepted

Output 2

Enter your name:
Rajeev
Enter your e-mail:
rajeev.123@gmail.com
Enter your age:
25
e-mail value accepted

Example 2

 Live Demo

import java.util.Scanner;
public class Example {
   public static void main(String args[]) {
      //Reading String from user
      System.out.println("Enter email address: ");
      Scanner sc = new Scanner(System.in);
      String e_mail = sc.nextLine();
      //Regular expression
      String regex = "^([a-zA-Z0-9._%+-]+@[a-zA-Z0-9.-]+\.[a-zA-Z]{2,6})?$";
      boolean result = e_mail.matches(regex);
      if(result) {
         System.out.println("Valid match");
      } else {
         System.out.println("Invalid match");
      }
   }
}

Output 1

Enter email address:
rajeev.123@gmail.com
Valid match

Output 2

Enter email address:
Valid match
Updated on: 2020-01-10T11:39:06+05:30

289 Views

Kickstart Your Career

Get certified by completing the course

Get Started
Advertisements