Correo electrónico Java regex

En primer lugar, sé que no se recomienda usar expresiones regulares para el correo electrónico, pero tengo que probarlo.

Tengo esta expresión regular:

\b[A-Z0-9._%-]+@[A-Z0-9.-]+\.[A-Z]{2,4}\b

En Java, hice esto:

Pattern p = Pattern.compile("\\b[A-Z0-9._%-]+@[A-Z0-9.-]+\\.[A-Z]{2,4}\\b");
Matcher m = p.matcher("[email protected]");

if (m.find())
    System.out.println("Correct!");

Sin embargo, la expresión regular falla independientemente de si el correo electrónico está bien formado o no. Un "buscar y reemplazar" dentro de Eclipse funciona bien con la misma expresión regular.

¿Alguna idea?

Gracias,

FWIW, aquí está el código Java que usamos para validar direcciones de correo electrónico. Los Regexp son muy similares:

public static final Pattern VALID_EMAIL_ADDRESS_REGEX = 
    Pattern.compile("^[A-Z0-9._%+-]+@[A-Z0-9.-]+\\.[A-Z]{2,6}$", Pattern.CASE_INSENSITIVE);

public static boolean validate(String emailStr) {
        Matcher matcher = VALID_EMAIL_ADDRESS_REGEX.matcher(emailStr);
        return matcher.find();
}

Funciona de forma bastante fiable.

Aquí está la expresión regular compatible con RFC822 adaptada para Java:

Pattern ptr = Pattern.compile("(?:(?:\\r\\n)?[ \\t])*(?:(?:(?:[^()<>@,;:\\\\\".\\[\\] \\000-\\031]+(?:(?:(?:\\r\\n)?[ \\t])+|\\Z|(?=[\\[\"()<>@,;:\\\\\".\\[\\]]))|\"(?:[^\\\"\\r\\\\]|\\\\.|(?:(?:\\r\\n)?[ \\t]))*\"(?:(?:\\r\\n)?[ \\t])*)(?:\\.(?:(?:\\r\\n)?[ \\t])*(?:[^()<>@,;:\\\\\".\\[\\] \\000-\\031]+(?:(?:(?:\\r\\n)?[ \\t])+|\\Z|(?=[\\[\"()<>@,;:\\\\\".\\[\\]]))|\"(?:[^\\\"\\r\\\\]|\\\\.|(?:(?:\\r\\n)?[ \\t]))*\"(?:(?:\\r\\n)?[ \\t])*))*@(?:(?:\\r\\n)?[ \\t])*(?:[^()<>@,;:\\\\\".\\[\\] \\000-\\031]+(?:(?:(?:\\r\\n)?[ \\t])+|\\Z|(?=[\\[\"()<>@,;:\\\\\".\\[\\]]))|\\[([^\\[\\]\\r\\\\]|\\\\.)*\\](?:(?:\\r\\n)?[ \\t])*)(?:\\.(?:(?:\\r\\n)?[ \\t])*(?:[^()<>@,;:\\\\\".\\[\\] \\000-\\031]+(?:(?:(?:\\r\\n)?[ \\t])+|\\Z|(?=[\\[\"()<>@,;:\\\\\".\\[\\]]))|\\[([^\\[\\]\\r\\\\]|\\\\.)*\\](?:(?:\\r\\n)?[ \\t])*))*|(?:[^()<>@,;:\\\\\".\\[\\] \\000-\\031]+(?:(?:(?:\\r\\n)?[ \\t])+|\\Z|(?=[\\[\"()<>@,;:\\\\\".\\[\\]]))|\"(?:[^\\\"\\r\\\\]|\\\\.|(?:(?:\\r\\n)?[ \\t]))*\"(?:(?:\\r\\n)?[ \\t])*)*\\<(?:(?:\\r\\n)?[ \\t])*(?:@(?:[^()<>@,;:\\\\\".\\[\\] \\000-\\031]+(?:(?:(?:\\r\\n)?[ \\t])+|\\Z|(?=[\\[\"()<>@,;:\\\\\".\\[\\]]))|\\[([^\\[\\]\\r\\\\]|\\\\.)*\\](?:(?:\\r\\n)?[ \\t])*)(?:\\.(?:(?:\\r\\n)?[ \\t])*(?:[^()<>@,;:\\\\\".\\[\\] \\000-\\031]+(?:(?:(?:\\r\\n)?[ \\t])+|\\Z|(?=[\\[\"()<>@,;:\\\\\".\\[\\]]))|\\[([^\\[\\]\\r\\\\]|\\\\.)*\\](?:(?:\\r\\n)?[ \\t])*))*(?:,@(?:(?:\\r\\n)?[ \\t])*(?:[^()<>@,;:\\\\\".\\[\\] \\000-\\031]+(?:(?:(?:\\r\\n)?[ \\t])+|\\Z|(?=[\\[\"()<>@,;:\\\\\".\\[\\]]))|\\[([^\\[\\]\\r\\\\]|\\\\.)*\\](?:(?:\\r\\n)?[ \\t])*)(?:\\.(?:(?:\\r\\n)?[ \\t])*(?:[^()<>@,;:\\\\\".\\[\\] \\000-\\031]+(?:(?:(?:\\r\\n)?[ \\t])+|\\Z|(?=[\\[\"()<>@,;:\\\\\".\\[\\]]))|\\[([^\\[\\]\\r\\\\]|\\\\.)*\\](?:(?:\\r\\n)?[ \\t])*))*)*:(?:(?:\\r\\n)?[ \\t])*)?(?:[^()<>@,;:\\\\\".\\[\\] \\000-\\031]+(?:(?:(?:\\r\\n)?[ \\t])+|\\Z|(?=[\\[\"()<>@,;:\\\\\".\\[\\]]))|\"(?:[^\\\"\\r\\\\]|\\\\.|(?:(?:\\r\\n)?[ \\t]))*\"(?:(?:\\r\\n)?[ \\t])*)(?:\\.(?:(?:\\r\\n)?[ \\t])*(?:[^()<>@,;:\\\\\".\\[\\] \\000-\\031]+(?:(?:(?:\\r\\n)?[ \\t])+|\\Z|(?=[\\[\"()<>@,;:\\\\\".\\[\\]]))|\"(?:[^\\\"\\r\\\\]|\\\\.|(?:(?:\\r\\n)?[ \\t]))*\"(?:(?:\\r\\n)?[ \\t])*))*@(?:(?:\\r\\n)?[ \\t])*(?:[^()<>@,;:\\\\\".\\[\\] \\000-\\031]+(?:(?:(?:\\r\\n)?[ \\t])+|\\Z|(?=[\\[\"()<>@,;:\\\\\".\\[\\]]))|\\[([^\\[\\]\\r\\\\]|\\\\.)*\\](?:(?:\\r\\n)?[ \\t])*)(?:\\.(?:(?:\\r\\n)?[ \\t])*(?:[^()<>@,;:\\\\\".\\[\\] \\000-\\031]+(?:(?:(?:\\r\\n)?[ \\t])+|\\Z|(?=[\\[\"()<>@,;:\\\\\".\\[\\]]))|\\[([^\\[\\]\\r\\\\]|\\\\.)*\\](?:(?:\\r\\n)?[ \\t])*))*\\>(?:(?:\\r\\n)?[ \\t])*)|(?:[^()<>@,;:\\\\\".\\[\\] \\000-\\031]+(?:(?:(?:\\r\\n)?[ \\t])+|\\Z|(?=[\\[\"()<>@,;:\\\\\".\\[\\]]))|\"(?:[^\\\"\\r\\\\]|\\\\.|(?:(?:\\r\\n)?[ \\t]))*\"(?:(?:\\r\\n)?[ \\t])*)*:(?:(?:\\r\\n)?[ \\t])*(?:(?:(?:[^()<>@,;:\\\\\".\\[\\] \\000-\\031]+(?:(?:(?:\\r\\n)?[ \\t])+|\\Z|(?=[\\[\"()<>@,;:\\\\\".\\[\\]]))|\"(?:[^\\\"\\r\\\\]|\\\\.|(?:(?:\\r\\n)?[ \\t]))*\"(?:(?:\\r\\n)?[ \\t])*)(?:\\.(?:(?:\\r\\n)?[ \\t])*(?:[^()<>@,;:\\\\\".\\[\\] \\000-\\031]+(?:(?:(?:\\r\\n)?[ \\t])+|\\Z|(?=[\\[\"()<>@,;:\\\\\".\\[\\]]))|\"(?:[^\\\"\\r\\\\]|\\\\.|(?:(?:\\r\\n)?[ \\t]))*\"(?:(?:\\r\\n)?[ \\t])*))*@(?:(?:\\r\\n)?[ \\t])*(?:[^()<>@,;:\\\\\".\\[\\] \\000-\\031]+(?:(?:(?:\\r\\n)?[ \\t])+|\\Z|(?=[\\[\"()<>@,;:\\\\\".\\[\\]]))|\\[([^\\[\\]\\r\\\\]|\\\\.)*\\](?:(?:\\r\\n)?[ \\t])*)(?:\\.(?:(?:\\r\\n)?[ \\t])*(?:[^()<>@,;:\\\\\".\\[\\] \\000-\\031]+(?:(?:(?:\\r\\n)?[ \\t])+|\\Z|(?=[\\[\"()<>@,;:\\\\\".\\[\\]]))|\\[([^\\[\\]\\r\\\\]|\\\\.)*\\](?:(?:\\r\\n)?[ \\t])*))*|(?:[^()<>@,;:\\\\\".\\[\\] \\000-\\031]+(?:(?:(?:\\r\\n)?[ \\t])+|\\Z|(?=[\\[\"()<>@,;:\\\\\".\\[\\]]))|\"(?:[^\\\"\\r\\\\]|\\\\.|(?:(?:\\r\\n)?[ \\t]))*\"(?:(?:\\r\\n)?[ \\t])*)*\\<(?:(?:\\r\\n)?[ \\t])*(?:@(?:[^()<>@,;:\\\\\".\\[\\] \\000-\\031]+(?:(?:(?:\\r\\n)?[ \\t])+|\\Z|(?=[\\[\"()<>@,;:\\\\\".\\[\\]]))|\\[([^\\[\\]\\r\\\\]|\\\\.)*\\](?:(?:\\r\\n)?[ \\t])*)(?:\\.(?:(?:\\r\\n)?[ \\t])*(?:[^()<>@,;:\\\\\".\\[\\] \\000-\\031]+(?:(?:(?:\\r\\n)?[ \\t])+|\\Z|(?=[\\[\"()<>@,;:\\\\\".\\[\\]]))|\\[([^\\[\\]\\r\\\\]|\\\\.)*\\](?:(?:\\r\\n)?[ \\t])*))*(?:,@(?:(?:\\r\\n)?[ \\t])*(?:[^()<>@,;:\\\\\".\\[\\] \\000-\\031]+(?:(?:(?:\\r\\n)?[ \\t])+|\\Z|(?=[\\[\"()<>@,;:\\\\\".\\[\\]]))|\\[([^\\[\\]\\r\\\\]|\\\\.)*\\](?:(?:\\r\\n)?[ \\t])*)(?:\\.(?:(?:\\r\\n)?[ \\t])*(?:[^()<>@,;:\\\\\".\\[\\] \\000-\\031]+(?:(?:(?:\\r\\n)?[ \\t])+|\\Z|(?=[\\[\"()<>@,;:\\\\\".\\[\\]]))|\\[([^\\[\\]\\r\\\\]|\\\\.)*\\](?:(?:\\r\\n)?[ \\t])*))*)*:(?:(?:\\r\\n)?[ \\t])*)?(?:[^()<>@,;:\\\\\".\\[\\] \\000-\\031]+(?:(?:(?:\\r\\n)?[ \\t])+|\\Z|(?=[\\[\"()<>@,;:\\\\\".\\[\\]]))|\"(?:[^\\\"\\r\\\\]|\\\\.|(?:(?:\\r\\n)?[ \\t]))*\"(?:(?:\\r\\n)?[ \\t])*)(?:\\.(?:(?:\\r\\n)?[ \\t])*(?:[^()<>@,;:\\\\\".\\[\\] \\000-\\031]+(?:(?:(?:\\r\\n)?[ \\t])+|\\Z|(?=[\\[\"()<>@,;:\\\\\".\\[\\]]))|\"(?:[^\\\"\\r\\\\]|\\\\.|(?:(?:\\r\\n)?[ \\t]))*\"(?:(?:\\r\\n)?[ \\t])*))*@(?:(?:\\r\\n)?[ \\t])*(?:[^()<>@,;:\\\\\".\\[\\] \\000-\\031]+(?:(?:(?:\\r\\n)?[ \\t])+|\\Z|(?=[\\[\"()<>@,;:\\\\\".\\[\\]]))|\\[([^\\[\\]\\r\\\\]|\\\\.)*\\](?:(?:\\r\\n)?[ \\t])*)(?:\\.(?:(?:\\r\\n)?[ \\t])*(?:[^()<>@,;:\\\\\".\\[\\] \\000-\\031]+(?:(?:(?:\\r\\n)?[ \\t])+|\\Z|(?=[\\[\"()<>@,;:\\\\\".\\[\\]]))|\\[([^\\[\\]\\r\\\\]|\\\\.)*\\](?:(?:\\r\\n)?[ \\t])*))*\\>(?:(?:\\r\\n)?[ \\t])*)(?:,\\s*(?:(?:[^()<>@,;:\\\\\".\\[\\] \\000-\\031]+(?:(?:(?:\\r\\n)?[ \\t])+|\\Z|(?=[\\[\"()<>@,;:\\\\\".\\[\\]]))|\"(?:[^\\\"\\r\\\\]|\\\\.|(?:(?:\\r\\n)?[ \\t]))*\"(?:(?:\\r\\n)?[ \\t])*)(?:\\.(?:(?:\\r\\n)?[ \\t])*(?:[^()<>@,;:\\\\\".\\[\\] \\000-\\031]+(?:(?:(?:\\r\\n)?[ \\t])+|\\Z|(?=[\\[\"()<>@,;:\\\\\".\\[\\]]))|\"(?:[^\\\"\\r\\\\]|\\\\.|(?:(?:\\r\\n)?[ \\t]))*\"(?:(?:\\r\\n)?[ \\t])*))*@(?:(?:\\r\\n)?[ \\t])*(?:[^()<>@,;:\\\\\".\\[\\] \\000-\\031]+(?:(?:(?:\\r\\n)?[ \\t])+|\\Z|(?=[\\[\"()<>@,;:\\\\\".\\[\\]]))|\\[([^\\[\\]\\r\\\\]|\\\\.)*\\](?:(?:\\r\\n)?[ \\t])*)(?:\\.(?:(?:\\r\\n)?[ \\t])*(?:[^()<>@,;:\\\\\".\\[\\] \\000-\\031]+(?:(?:(?:\\r\\n)?[ \\t])+|\\Z|(?=[\\[\"()<>@,;:\\\\\".\\[\\]]))|\\[([^\\[\\]\\r\\\\]|\\\\.)*\\](?:(?:\\r\\n)?[ \\t])*))*|(?:[^()<>@,;:\\\\\".\\[\\] \\000-\\031]+(?:(?:(?:\\r\\n)?[ \\t])+|\\Z|(?=[\\[\"()<>@,;:\\\\\".\\[\\]]))|\"(?:[^\\\"\\r\\\\]|\\\\.|(?:(?:\\r\\n)?[ \\t]))*\"(?:(?:\\r\\n)?[ \\t])*)*\\<(?:(?:\\r\\n)?[ \\t])*(?:@(?:[^()<>@,;:\\\\\".\\[\\] \\000-\\031]+(?:(?:(?:\\r\\n)?[ \\t])+|\\Z|(?=[\\[\"()<>@,;:\\\\\".\\[\\]]))|\\[([^\\[\\]\\r\\\\]|\\\\.)*\\](?:(?:\\r\\n)?[ \\t])*)(?:\\.(?:(?:\\r\\n)?[ \\t])*(?:[^()<>@,;:\\\\\".\\[\\] \\000-\\031]+(?:(?:(?:\\r\\n)?[ \\t])+|\\Z|(?=[\\[\"()<>@,;:\\\\\".\\[\\]]))|\\[([^\\[\\]\\r\\\\]|\\\\.)*\\](?:(?:\\r\\n)?[ \\t])*))*(?:,@(?:(?:\\r\\n)?[ \\t])*(?:[^()<>@,;:\\\\\".\\[\\] \\000-\\031]+(?:(?:(?:\\r\\n)?[ \\t])+|\\Z|(?=[\\[\"()<>@,;:\\\\\".\\[\\]]))|\\[([^\\[\\]\\r\\\\]|\\\\.)*\\](?:(?:\\r\\n)?[ \\t])*)(?:\\.(?:(?:\\r\\n)?[ \\t])*(?:[^()<>@,;:\\\\\".\\[\\] \\000-\\031]+(?:(?:(?:\\r\\n)?[ \\t])+|\\Z|(?=[\\[\"()<>@,;:\\\\\".\\[\\]]))|\\[([^\\[\\]\\r\\\\]|\\\\.)*\\](?:(?:\\r\\n)?[ \\t])*))*)*:(?:(?:\\r\\n)?[ \\t])*)?(?:[^()<>@,;:\\\\\".\\[\\] \\000-\\031]+(?:(?:(?:\\r\\n)?[ \\t])+|\\Z|(?=[\\[\"()<>@,;:\\\\\".\\[\\]]))|\"(?:[^\\\"\\r\\\\]|\\\\.|(?:(?:\\r\\n)?[ \\t]))*\"(?:(?:\\r\\n)?[ \\t])*)(?:\\.(?:(?:\\r\\n)?[ \\t])*(?:[^()<>@,;:\\\\\".\\[\\] \\000-\\031]+(?:(?:(?:\\r\\n)?[ \\t])+|\\Z|(?=[\\[\"()<>@,;:\\\\\".\\[\\]]))|\"(?:[^\\\"\\r\\\\]|\\\\.|(?:(?:\\r\\n)?[ \\t]))*\"(?:(?:\\r\\n)?[ \\t])*))*@(?:(?:\\r\\n)?[ \\t])*(?:[^()<>@,;:\\\\\".\\[\\] \\000-\\031]+(?:(?:(?:\\r\\n)?[ \\t])+|\\Z|(?=[\\[\"()<>@,;:\\\\\".\\[\\]]))|\\[([^\\[\\]\\r\\\\]|\\\\.)*\\](?:(?:\\r\\n)?[ \\t])*)(?:\\.(?:(?:\\r\\n)?[ \\t])*(?:[^()<>@,;:\\\\\".\\[\\] \\000-\\031]+(?:(?:(?:\\r\\n)?[ \\t])+|\\Z|(?=[\\[\"()<>@,;:\\\\\".\\[\\]]))|\\[([^\\[\\]\\r\\\\]|\\\\.)*\\](?:(?:\\r\\n)?[ \\t])*))*\\>(?:(?:\\r\\n)?[ \\t])*))*)?;\\s*)");
String[] emails = { "\"Fred Bloggs\"@example.com", "[email protected]", "Chuck Norris <[email protected]>", "webmaster@müller.de", "[email protected]" };
for (String email : emails) {
    System.out.println(email + " is " + (ptr.matcher(email).matches() ? "valid" : "invalid"));
}

Salida:

"Fred Bloggs"@example.com is valid
user@.invalid.com is invalid
Chuck Norris <gmail@chucknorris.com> is valid
webmaster@müller.de is valid
matteo@78.47.122.114 is valid

La expresión regular se toma de esta publicación: Correo :: RFC822 :: Dirección: validación de dirección basada en expresiones regulares . Los resultados deben coincidir con la versión en línea .

No lo hagas. Nunca terminarás con una expresión válida.

Por ejemplo, estas son todas direcciones de correo electrónico válidas:

"Abc\@def"@example.com
"Fred Bloggs"@example.com
"Joe\\Blow"@example.com
"Abc@def"@example.com
customer/department=shipping@examp­ le.com
$A12345@example.com
!def!xyz%abc@example.com
_somename@example.com
matteo(this is a comment).corti@example.com
root@[127.0.0.1]

Solo por mencionar algunos problemas:

• no considera las muchas formas de especificar un host (por ejemplo, por la dirección IP)
• extrañas caracteres válidos
• echas de menos nombres de dominio que no sean ASCII

Antes incluso de comenzar, verifique las RFC correspondientes

Eso es porque estás olvidando la insensibilidad a mayúsculas y minúsculas:

Pattern regex = Pattern.compile("\\b[\\w.%-]+@[-.\\w]+\\.[A-Za-z]{2,4}\\b");

Esto coincide con su ejemplo, aunque ignora muchos correos electrónicos válidos.

Otra alternativa simple para validar el 99% de los correos electrónicos

public static final String EMAIL_VERIFICATION = "^([\\w-\\.]+){1,64}@([\\w&&[^_]]+){2,255}.[a-z]{2,}$";

Esta es una expresión regular válida para validar correos electrónicos. Es totalmente compatible con RFC822 y acepta direcciones IP y nombres de servidor (para propósitos de intranet).

public static boolean isEmailValid(String email) {
    final Pattern EMAIL_REGEX = Pattern.compile("[a-z0-9!#$%&'*+/=?^_`{|}~-]+(?:.[a-z0-9!#$%&'*+/=?^_`{|}~-]+)*@(?:[a-z0-9](?:[a-z0-9-]*[a-z0-9])?.)+[a-z0-9](?:[a-z0-9-]*[a-z0-9])?", Pattern.CASE_INSENSITIVE);
    return EMAIL_REGEX.matcher(email).matches();
}

Aquí hay algunos ejemplos de salida, cuando llama isEmailValid(emailVariable):

john@somewhere.com // valid
john.foo@somewhere.com // valid
john.foo+label@somewhere.com // valid (with +label - Gmail accepts it!)
john@192.168.1.10 // valid (with IP addresses)
john+label@192.168.1.10 // valid (with +label and IP address)
john.foo@someserver // valid (with no first domain level)
JOHN.FOO@somewhere.com // valid (case insensitive)
@someserver // invalid
@someserver.com // invalid
john@. // invalid
.@somewhere.com // invalid

¿Está el mecanizado configurado en CASE_INSENSITIVE ?

Puede utilizar este método para validar la dirección de correo electrónico en java.

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();

    }
}

Formato de correo electrónico general (RE) que incluye también dominios como co.in, co.uk, com, outlook.com, etc.

Y la regla dice que:

• Letras inglesas mayúsculas y minúsculas (az, AZ)
• Dígitos del 0 al 9
• Caracteres ! # $% & '* + - / =? ^ _ `{| } ~ Carácter.

• (punto, punto, punto) siempre que no sea el primer ni el último carácter, y siempre que no aparezca dos o más veces consecutivas.

  [a-zA-Z0-9]+[._a-zA-Z0-9!#$%&'*+-/=?^_`{|}~]*[a-zA-Z]*@[a-zA-Z0-9]{2,8}.[a-zA-Z.]{2,6}

Modificación de la respuesta de Armer B. que no validó los correos electrónicos que terminan con '.co.uk'

public static boolean emailValidate(String email) {
    Matcher matcher = Pattern.compile("^([\\w-\\.]+){1,64}@([\\w&&[^_]]+){2,255}(.[a-z]{2,3})+$|^$", Pattern.CASE_INSENSITIVE).matcher(email);

    return matcher.find();
}

Regex: ^[\\w!#$%&’*+/=?{|} ~ ^ -] + (?: \. [\ W! # $% & '* + / =?{|}~^-]+)*@(?:[a-zA-Z0-9-]+\\.)+[a-zA-Z]{2,6}$

public static boolean isValidEmailId(String email) {
        String emailPattern = "^[\\w!#$%&’*+/=?`{|}~^-]+(?:\\.[\\w!#$%&’*+/=?`{|}~^-]+)*@(?:[a-zA-Z0-9-]+\\.)+[a-zA-Z]{2,6}$";
        Pattern p = Pattern.compile(emailPattern);
        Matcher m = p.matcher(email);
        return m.matches();
    }

Si quieres permitir personajes que no sean latain, este funciona bastante bien para mí.

"^[\\p{L}\\p{N}\\._%+-]+@[\\p{L}\\p{N}\\.\\-]+\\.[\\p{L}]{2,}$"

No permite direcciones IP después de @, pero la mayoría de los correos electrónicos válidos en el origen de [email protected]pueden validarse con él. \p{L}valida UTF-Letters y \p{N}valida UTF-Numbers. Puede consultar este documento para obtener más información.

Pruebe el siguiente código para el formato de correo electrónico

jsmith@example.com

1ra parte -jsmith 2da parte[email protected]

1. In the 1 part it will allow 0-9,A-Z,dot sign(.),underscore sign(_)
 2. In the 2 part it will allow A-Z, must be @ and .

^[a-zA-Z0-9_.]+@[a-zA-Z.]+?\.[a-zA-Z]{2,3}$

He probado esto a continuación regular expressionpara puntos consecutivos únicos y múltiples en el domainnombre:

([A-Za-z0-9-_.]+@[A-Za-z0-9-_]+(?:\.[A-Za-z0-9]+)+)

y aquí están los ejemplos que fueron completamente cumplidos por arriba regex.

End_user@live.com
End.u@exm-tech.net
enduser9876@gmail.in
end_user@mywebsite.ac.in.gui
Another984.User2@mail.edu.sg
Another987_User5@mail.show.au
Slow_User@example_domain.au.in
iamthemostsimpleremailhere@example.com

He intentado cubrir el máximo comúnmente utilizado email id's validation por este ilustrado anteriormente regexy, sin embargo, funciona ...

Si aún sabe que algunos de los usados ​​consecuentemente email id'squedaron aquí, ¡hágamelo saber en la sección de comentarios!

String emailRegex = "[a-zA-Z0-9_.]+@[a-zA-Z0-9]+.[a-zA-Z]{2,3}[.] {0,1}[a-zA-Z]+";
Pattern.matches(emailRegex,"You_Input_Mail_Id");

Esta es la expresión regular para que coincida con direcciones de correo electrónico válidas.

puede usar una expresión regular simple para validar la identificación del correo electrónico,

public boolean validateEmail(String email){
  return Pattern.matches("[_a-zA-Z1-9]+(\\.[A-Za-z0-9]*)*@[A-Za-z0-9]+\\.[A-Za-z0-9]+(\\.[A-Za-z0-9]*)*", email)
}

Descripción:

1. [_a-zA-Z1-9] + - aceptará todo AZ, az, 0-9 y _ (+ significa que debe ocurrir)
2. (\. [A-Za-z0-9] ) - es opcional que aceptará. y AZ, az, 0-9 (* significa que es opcional)
3. @ [A-Za-z0-9] + - aceptará @ y AZ, az, 0-9
4. \. [A-Za-z0-9] + - es para. y AZ, az, 0-9
5. (\. [A-Za-z0-9] ) - ocurre ,. pero es opcional

Puede verificar si los correos electrónicos son válidos o no utilizando estas librerías y, por supuesto, puede agregar una matriz para este proyecto siguiente.

import org.apache.commons.validator.routines.EmailValidator;

public class Email{
    public static void main(String[] args){
        EmailValidator email = EmailVlidator.getInstance();
        boolean val = email.isValid("[email protected]");
        System.out.println("Mail is: "+val);
        val = email.isValid("hans.riguer.hotmsil.com");
        System.out.print("Mail is: "+val");
    }
}

salida:

El correo es: verdadero

El correo es: falso

import java.util.Scanner;

public class CheckingTheEmailPassword {

    public static void main(String[] args) {
        String email = null;
        String password = null;
        Boolean password_valid = false;
        Boolean email_valid = false;

        Scanner input = new Scanner(System.in);
        do {
            System.out.println("Enter your email: ");
            email = input.nextLine();

            System.out.println("Enter your passsword: ");
            password = input.nextLine();

            // checks for words,numbers before @symbol and between "@" and ".".
            // Checks only 2 or 3 alphabets after "."
            if (email.matches("[\\w]+@[\\w]+\\.[a-zA-Z]{2,3}"))
                email_valid = true;
            else
                email_valid = false;

            // checks for NOT words,numbers,underscore and whitespace.
            // checks if special characters present
            if ((password.matches(".*[^\\w\\s].*")) &&
            // checks alphabets present
                    (password.matches(".*[a-zA-Z].*")) &&
                    // checks numbers present
                    (password.matches(".*[0-9].*")) &&
                    // checks length
                    (password.length() >= 8))
                password_valid = true;
            else
                password_valid = false;

            if (password_valid && email_valid)
                System.out.println(" Welcome User!!");
            else {
                if (!email_valid)
                    System.out.println(" Re-enter your email: ");
                if (!password_valid)
                    System.out.println(" Re-enter your password: ");
            }

        } while (!email_valid || !password_valid);

        input.close();

    }

}

Gracias a la respuesta de @Jason Buberel, creo que las letras minúsculas deben ser validadas por RegEX. Entonces lo siguiente es correcto:

[A-Za-z0-9._%+-]+@[A-Za-z0-9.-]+\.[A-Za-z]{2,6}

¡Ahora, tanto [email protected] como [email protected] son válidos!
Tenga en cuenta que \. debería ser \\. escapar . y tener \. sí mismo. Dado que ,. es un carácter significativo en Java RegEX significa todos los caracteres.

Regex para validación similar a Facebook:

public static final String REGEX_EMAIL_VALIDATION = "^[\\w-\\+]+(\\.[\\w]+)*@[\\w-]+(\\.[\\w]+)*(\\.[a-zA-Z]{2,})$";

Dto para pruebas unitarias (con Lombok):

@Data
@Accessors(chain = true)
@FieldDefaults(level = AccessLevel.PRIVATE)
public class UserCreateDto {

    @NotNull
    @Pattern(regexp = REGEX_EMAIL_VALIDATION)
    @Size(min = 1, max = 254)
    String email;
}

Correos electrónicos válidos / no válidos a continuación con pruebas unitarias:

public class UserCreateValidationDtoTest {

private static final String[] VALID_EMAILS = new String[]{"[email protected]", "[email protected]",
        "[email protected]", "[email protected]", "[email protected]",
        "[email protected]", "[email protected]", "[email protected]",
        "[email protected]", "[email protected]", "[email protected]"};
private static final String[] INVALID_EMAILS = new String[]{"あいうえお@example.com", "email@111",
        "email", "[email protected]", "email123@gmail.", "[email protected]", "[email protected]",
        "[email protected]", "email()*@gmAil.com", "eEmail()*@gmail.com", "email@%*.com", "[email protected]",
        "[email protected]", "email@[email protected]", "[email protected]."};
private Validator validator;

@Before
public void setUp() throws Exception {
    ValidatorFactory factory = Validation.buildDefaultValidatorFactory();
    validator = factory.getValidator();
}

@Test
public void emailValidationShouldBeValid() throws Exception {
    Arrays.stream(VALID_EMAILS)
            .forEach(email -> {
                        Set<ConstraintViolation<UserCreateDto>> violations = validateEmail(
                                new UserCreateDto().setEmail(email));
                        System.out.println("Email: " + email + ", violations: " + violations);
                        Assert.assertTrue(violations.isEmpty());
                    }
            );
}

@Test
public void emailValidationShouldBeNotValid() throws Exception {
    Arrays.stream(INVALID_EMAILS)
            .forEach(email -> {
                        Set<ConstraintViolation<UserCreateDto>> violations = validateEmail(
                                new UserCreateDto().setEmail(email));
                        System.out.println("Email: " + email + ", violations: " + violations);
                        Assert.assertTrue(!violations.isEmpty());
                    }
            );
}


private Set<ConstraintViolation<UserCreateDto>> validateEmail(UserCreateDto user) {
    String emailFieldName = "email";
    return validator.validateProperty(user, emailFieldName);
}

}