使用带有posix语法的正则表达式来验证电子邮件地址

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();
    }
}

Answer 1

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 +