Validating email format in java

Question

I need to validate an email pattern which starts with an alphabat and ends with @gmail.com. Following is my code.

 public static boolean isValidEmail(String email)
 {
    String endPattern = "@gmail.com";

    if(null == email){
        return false;
    }   
    if(email.length()<10){
        return false;
    }   
    if(!email.endsWith(endPattern)){
        return false;
    }
    String[] strArr = email.split(endPattern);  
    String mailId = strArr[0];  
    if(!Character.isLetter((mailId.charAt(0)))){
        return false;
    }   
    return true;
  }

Is there a better way to acheive this? A regex or a better code?

score 4 · Accepted Answer · answered Oct 17 '14 at 11:13

4

Use a regex

public static boolean isValidEmail(String email)
{
    if (email != null)
    {
        Pattern p = Pattern.compile("^[A-Za-z].*?@gmail\\.com$");
        Matcher m = p.matcher(email);
        return m.find();
    }
    return false;
}

answered Oct 17 '14 at 11:13

ToYonos

16,469
2
54
70

Avinash Raj · Answer 2 · 2014-10-17T11:14:56.313

1

Use matches method to check for a string whether it starts with an alphabet or not and ends with the string @gmail.com or not

System.out.println("foo@gmail.com".matches("[A-Za-z].*?@gmail\\.com"));
System.out.println("8foo@gmail.com".matches("[A-Za-z].*?@gmail\\.com"));

Output:

true
false

edited Oct 17 '14 at 11:14

answered Oct 17 '14 at 11:09

Avinash Raj

172,303
28
230
274

Thusitha Thilina Dayaratne · Answer 3 · 2014-10-17T11:27:19.217

1

According to the Google,

e-mail address

should start with a letter or number
can only contain letters (a-z), numbers, and periods.
should be at least 6 characters

Regex should be

Pattern p = Pattern.compile("^[_A-Za-z0-9]+[\\.[A-Za-z0-9]{5,}@gmail\\.com$");

edited Oct 17 '14 at 11:27

answered Oct 17 '14 at 11:15

Thusitha Thilina Dayaratne

5,666
4
42
69

Way too limiting unless gmail has strict requirements listed somewhere. – nablex Oct 17 '14 at 11:18
According to Google you can only use letters (a-z), numbers, and periods. – Thusitha Thilina Dayaratne Oct 17 '14 at 11:19
Nice, didn't know that, is there a link to this requirement? (for future reference) – nablex Oct 17 '14 at 11:20
Well there is no document. But when you are creating a new email account google validate and show a message saying "Please use only letters (a-z), numbers, and periods." – Thusitha Thilina Dayaratne Oct 17 '14 at 11:22
an email address can contain the "+" symbol as well. – Manu May 05 '17 at 09:41

score 1 · Answer 4 · answered Oct 17 '14 at 11:25

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);
   }
 }

score 1 · Answer 5 · edited Oct 17 '14 at 11:28

package com.mkyong.regex;

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

public class EmailValidator {

    private Pattern pattern;
    private Matcher matcher;

    private static final String EMAIL_PATTERN = 
        "^[_A-Za-z0-9-\\+]+(\\.[_A-Za-z0-9-]+)*@"
        + "[A-Za-z0-9-]+(\\.[A-Za-z0-9]+)*(\\.[A-Za-z]{2,})$";

    public EmailValidator() {
        pattern = Pattern.compile(EMAIL_PATTERN);
    }

    /**
     * Validate hex with regular expression
     * 
     * @param hex
     *            hex for validation
     * @return true valid hex, false invalid hex
     */
    public boolean validate(final String hex) {

        matcher = pattern.matcher(hex);
        return matcher.matches();

    }
}

score -1 · Answer 6 · answered Oct 17 '14 at 11:30

-1

This is the javascript code

         <script>
  function checkEmail()
      {
     var feedback="";
   var email=document.getElementById("email").value;
  var count=email.length;
  var atpos=email.indexOf('@');
   var atdot=email.lastIndexOf('.');
  var tld=email.substring(atdot);
     if(atpos<1 || atdot<1)
   {
   alert("Email is  Not Valid");
    }
      else if(atpos>atdot)
     {
   alert("Email is  Not Valid");
    }
   else{
   alert("Email is Valid");
       }
      }

answered Oct 17 '14 at 11:30

jyothi vishnumolakala

25
2

`Javascript != Java` – asontu Oct 17 '14 at 11:31
Clientside != Serverside – nablex Oct 17 '14 at 12:23

Validating email format in java

6 Answers6