using regex in java for validate email

Question

I am trying to validate a certain subset of the e-mail format with regular expressions, but what I've tried so far doesn't quite work. This is my regex (Java):

boolean x = l.matches(
    "^[_A-Za-z0-9-\\\\+]+(\\\\.[_A-Za-z0-9-]+)*@\"\n" +"+ \"[A-Za-z0-9-]+(\\\\.[A-Za-z0-9]+)*(\\\\.[A-Za-z]{2,})$"
);

Thse are the conditions that the string has to match:

Mail domain is from the list:
- www.fightclub.uk
- www.fightclub.lk
- www.fightclub.sa
- www.fightclub.cc
- www.fightclub.jp
- www.fightclub.se
- www.fightclub.xy
- www.fightclub.gi
- www.fightclub.rl
- www.fightclub.ss
username has 3 to 6 characters(only lowercase English letters and numbers)

examples:

[email protected] is valid

[email protected] is invalid

*..username has 3 to 6 characters(only lowercase English letters and numbers)..* -> `[a-z0-9]{6}` will do it for you. Rest you didn't provide the information for other half. — Am_I_Helpful, Jul 22 '17 at 19:12
See [*Java regex email*](https://stackoverflow.com/questions/8204680/java-regex-email). — Wiktor Stribiżew, Jul 22 '17 at 19:12
@WiktorStribiżew i tried with it also.but i faild. can u show me correct code.i am new for this — Intern, Jul 22 '17 at 19:14

Raman Sahasi · Accepted Answer · 2017-07-22T19:25:05.720

2

You can use:

^[a-z0-9]{3,6}@fightclub\.(?:uk|lk|sa|cc|jp|se|xy|gi|rl|ss)$

^ indicates start of string
[a-z0-9]{3,6} lowercase letters or number with length 3-6 characters
followed by @fightclub
followed by a period \.
followed by a list of domains (?: indicate that it's a non-capturing group. All your domain extensions are listed here.
$ indicates end of string

DEMO: https://regex101.com/r/rYYXYA/1

edited Jul 22 '17 at 19:25

answered Jul 22 '17 at 19:20

Raman Sahasi

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i got `valid` to `[email protected]` also.can u help me – Intern Jul 22 '17 at 19:23
@Intern I missed initial `^` and last `$`. Check regex again now. Also check the demo. – Raman Sahasi Jul 22 '17 at 19:25
no friend.i got `[email protected]` is `valid`.but should be invalid – Intern Jul 22 '17 at 19:29
question (too lazy to check): does regex101 support Java's idiom of regular expressions? – user85421 Jul 22 '17 at 19:29
@Intern I've created this online compilation of code with exacts same case. https://ideone.com/2X47NH . Its returning false. – Raman Sahasi Jul 22 '17 at 19:34
i tried with this code `boolean x=arr[j].matches("^[a-z0-9]{3,6}@fightclub\\.(?:uk|lk|sa|cc|jp|se|xy|gi|rl|ss)$"); if (x == false) { System.out.println("INVALID"); //return false; } else { System.out.println("VALID"); //return true; }` – Intern Jul 22 '17 at 19:36
1

@CarlosHeuberger I haven't encountered any situation until now where it won't work with java. However, you're right, this flavour isn't mentioned officially on their website. – Raman Sahasi Jul 22 '17 at 19:36
@Intern I'm not sure what's there in `arr[j]`. Please try it once after hardcoding the value like: `boolean x= "[email protected]".matches("^[a-z0-9]{3,6}@fightclub\\.(?:uk|lk|sa|cc|‌jp|se|xy|gi|rl|ss)$"‌);` – Raman Sahasi Jul 22 '17 at 19:38
@Intern or including the tested address in the message - the expression seems prefect for me. And tested on [RegEx Planet](http://fiddle.re/nzx1yd) – user85421 Jul 22 '17 at 19:40
you are correct mate.false is mine.so sorry and you are really great man.thank you very much – Intern Jul 22 '17 at 19:40

using regex in java for validate email

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