Using a regular expression with posix syntax to validate an email address

Question

Here is the validation that we have to use for email validation.

Using posix syntax:

^[[:graph:]]\\+@[[:graph:]]\\+\\.[[:graph:]]\\+$

I have written sample program to validate, but i have failed to give right Email address to fulfill posix syntax regular expression. Could you please any one help me out to correct my below Java example.

Java Example:

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


public class RegexMatches {

    public static void main(String args[]) {

      String email = "sudheer@gmail.com";
      String pattern ="^[[:graph:]]\\+@[[:graph:]]\\+\\.[[:graph:]]\\+$";
      //String pattern = ".+@.+\\.[a-z]+";// This is Working fine.

      if (!testRegex(email, pattern))
        System.out.println("Validator Exception");
      else
        System.out.println("Success");
    }

     public static boolean testRegex(String value, String regex) {
       Pattern pattern = Pattern.compile(regex);
       Matcher matcher = pattern.matcher(value);
       return matcher.matches();
    }
}

You have to use java syntax. Actually why do you think `"\\+"` is posix? This is escaping the `+` character. — akostadinov, Dec 02 '14 at 12:01
But still this code is working fine in my system, what's the error your getting? — smali, Dec 02 '14 at 12:03
I know this is for PHP but you should read it: http://stackoverflow.com/questions/201323/using-a-regular-expression-to-validate-an-email-address — m0skit0, Dec 02 '14 at 12:03

score 2 · Accepted Answer · answered Dec 02 '14 at 12:07

2

In java you can use:

String pattern ="^\\p{Graph}+@\\p{Graph}+\\.\\p{Graph}+$";

Reference

Use \\p{Graph} in Java for [[:graph:]] in POSIX
No need to use double escape quantifier +

answered Dec 02 '14 at 12:07

anubhava

761,203
64
569
643

What would the equivalent of `[[:graph:]_]` be? i.e. I want to include some other chars in the valid set for a particular token. – Sridhar Sarnobat Aug 24 '22 at 23:15
1

You can use character class in Java [\p{graph}_] – anubhava Aug 25 '22 at 03:24

Using a regular expression with posix syntax to validate an email address

Java Example:

1 Answers1