POSIX character equivalents in Java regular expressions

问题

I would like to use a regular expression like this in Java : [[=a=][=e=][=i=]].

But Java doesn't support the POSIX classes [=a=], [=e=] etc.

How can I do this? More precisely, is there a way to not use US-ASCII?

回答1:

Java does support posix character classes. The syntax is just different, for instance:

\p{Lower}
\p{Upper}
\p{ASCII}
\p{Alpha}
\p{Digit}
\p{Alnum}
\p{Punct}
\p{Graph}
\p{Print}
\p{Blank}
\p{Cntrl}
\p{XDigit}
\p{Space}

回答2:

Quoting from http://download.oracle.com/javase/1.6.0/docs/api/java/util/regex/Pattern.html

POSIX character classes (US-ASCII only)

\p{Lower}   A lower-case alphabetic character: [a-z]
\p{Upper}   An upper-case alphabetic character:[A-Z]
\p{ASCII}   All ASCII:[\x00-\x7F]
\p{Alpha}   An alphabetic character:[\p{Lower}\p{Upper}]
\p{Digit}   A decimal digit: [0-9]
\p{Alnum}   An alphanumeric character:[\p{Alpha}\p{Digit}]
\p{Punct}   Punctuation: One of !"#$%&'()*+,-./:;<=>?@[\]^_`{|}~
\p{Graph}   A visible character: [\p{Alnum}\p{Punct}]
\p{Print}   A printable character: [\p{Graph}\x20]
\p{Blank}   A space or a tab: [ \t]
\p{Cntrl}   A control character: [\x00-\x1F\x7F]
\p{XDigit}  A hexadecimal digit: [0-9a-fA-F]
\p{Space}   A whitespace character: [ \t\n\x0B\f\r]

回答3:

Copied from here

Java does not support POSIX bracket expressions, but does support POSIX character classes using the \p operator. Though the \p syntax is borrowed from the syntax for Unicode properties, the POSIX classes in Java only match ASCII characters as indicated below. The class names are case sensitive. Unlike the POSIX syntax which can only be used inside a bracket expression, Java's \p can be used inside and outside bracket expressions.

来源：https://stackoverflow.com/questions/6612870/posix-character-equivalents-in-java-regular-expressions