在正则表达式中使用\\ P {M}时，避免在电子邮件地址中使用2个“ @”符号

Question

I'm creating a validation regular expression for email addresses, the problem is that not only standard Latin chars are accepted but also Russian, Swedish and other languages that uses non Latin characters.

what i am using is the \\P{M} code, which basically allows the insertion of any Unicode codepoint. The problem is..... i off course want only 1 '@' (at) allowed, as according to standard syntax for email addresses. How can i avoid that? This is the RegEx i have so far:

input.matches("\\P{M}+@{1}\\P{M}+\\.[a-zA-Z]{2,6}$");

Thx for any advice, i have been trying with a lot of different combinations but nothing so far

Thank you

Answer 1

(?:[a-z0-9!#$%&'*+/=?^_`{|}~-]+(?:\.[a-z0-9!#$%&'*+/=?^_`{|}~-]+)*|"(?:[\x01-\x08\x0b\x0c\x0e-\x1f\x21\x23-\x5b\x5d-\x7f]|\\[\x01-\x09\x0b\x0c\x0e-\x7f])*")@(?:(?:[a-z0-9](?:[a-z0-9-]*[a-z0-9])?\.)+[a-z0-9](?:[a-z0-9-]*[a-z0-9])?|\[(?:(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.){3}(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?|[a-z0-9-]*[a-z0-9]:(?:[\x01-\x08\x0b\x0c\x0e-\x1f\x21-\x5a\x53-\x7f]|\\[\x01-\x09\x0b\x0c\x0e-\x7f])+)\])

http://www.regular-expressions.info/email.html