thx for ur contribution! besides, i got a good tool for testing regular expressions because of ur mention above~

btw, after i typed

[email protected]
[email protected]

in the left input area, it shows that the 2 lines don't match the regular expression above.

then i modified the lines to:

tommy@XX\XXX\
lemon-31@XX\XXX\

it shows they matched.

is there anything wrong?

email ending with ".com" is handled separately in code.
Here: https://github.com/Tencent/APIJSON/blob/master/APIJSONORM/src/main/java/apijson/StringUtil.java#L678

yeah, that's a problem of the legacy code, and i think we can remove the if clause here:
https://github.com/Tencent/APIJSON/blob/master/APIJSONORM/src/main/java/apijson/StringUtil.java#L678-L680

plus, if (isNotEmpty(email, true) == false) can be simplified to if (isEmpty(email, true))
https://github.com/Tencent/APIJSON/blob/master/APIJSONORM/src/main/java/apijson/StringUtil.java#L673

what do u think?

Absolutely, plus we can completely change the email regex to validate ".com" part within regex itself. Happy to do it.