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Email validation using regular expression in JSF 2 / PrimeFaces

I have an input field taking an email address:

<h:inputText value="#{register.user.email}" required="true" />

How can I validate the entered value as a valid email address using regex in JSF 2 / PrimeFaces?

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Nidheesh Avatar asked Oct 24 '11 11:10

Nidheesh


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How to validate Email in JSF?

To validate email, uses JSF <f:validateRegex> , and puts following regular expression. This regex should be able to validates most of the email format, and I'm using it for few projects. P.S For detail explanation, refer to this how to validate email address with regular expression.


4 Answers

All regular expression attempts to validate the email format based on Latin characters are broken. They do not support internationalized domain names which were available since May 2010. Yes, you read it right, non-Latin characters are since then allowed in domain names and thus also email addresses.

That are thus extremely a lot of possible characters to validate. Best is to just keep it simple. The following regex just validates the email format based on the occurrence of the @ and . characters.

<f:validateRegex pattern="([^.@]+)(\.[^.@]+)*@([^.@]+\.)+([^.@]+)" />

Again, this just validates the general email format, not whether the email itself is legit. One can still enter [email protected] as address and pass the validation. No one regex can cover that. If the validity of the email address is that important, combine it with an authentication system. Just send some kind of an activation email with a callback link to the email address in question and let the user login by email address.

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BalusC Avatar answered Nov 03 '22 02:11

BalusC


Here is how:

Using it myself...

<h:inputText id="email" value="#{settingsBean.aFriendEmail}" required="true" label="Email" validatorMessage="#{settingsBean.aFriendEmail} is not valid">
    <f:validateRegex pattern="[\w\.-]*[a-zA-Z0-9_]@[\w\.-]*[a-zA-Z0-9]\.[a-zA-Z][a-zA-Z\.]*[a-zA-Z]" />
</h:inputText>
<p:message for="email" />

Daniel.

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Daniel Avatar answered Nov 03 '22 02:11

Daniel


Here's my version and it works well :

<f:validateRegex pattern="^[_A-Za-z0-9-\+]+(\.[_A-Za-z0-9-]+)*@[A-Za-z0-9-]+(\.[A-Za-z0-9]+)*(\.[A-Za-z]{2,})$" />

And i made a demo here

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mkyong Avatar answered Nov 03 '22 00:11

mkyong


This one supports unicode domain names in email:

<f:validateRegex pattern="^[_A-Za-z0-9-\+]+(\.[_A-Za-z0-9-]+)*@[\p{L}\p{M}\p{N}.-]*(\.[\p{L}\p{M}]{2,})$" />

... and this one validates email only when email is entered (email is not required field in form):

<f:validateRegex pattern="(^[_A-Za-z0-9-\+]+(\.[_A-Za-z0-9-]+)*@[\p{L}\p{M}\p{N}.-]*(\.[\p{L}\p{M}]{2,})$)?" />
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Tere Hommikust Avatar answered Nov 03 '22 02:11

Tere Hommikust