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JAVA中正则表达式元字符

2017-08-05 21:40 232 查看


Summary of regular-expression constructs

ConstructMatches
 
Characters
xThe character x
\\The backslash character
\0nThe character with octal value 0n (0 <= n <= 7)
\0nnThe character with octal value 0nn (0 <= n <= 7)
\0mnnThe character with octal value 0mnn (0 <= m <= 3,
0 <= n <= 7)
\xhhThe character with hexadecimal value 0xhh
\uhhhhThe character with hexadecimal value 0xhhhh
\x{h...h}The character with hexadecimal value 0xh...h (
Character.MIN_CODE_POINT
  <= 0xh...h <= 
Character.MAX_CODE_POINT
)
\tThe tab character ('\u0009')
\nThe newline (line feed) character ('\u000A')
\rThe carriage-return character ('\u000D')
\fThe form-feed character ('\u000C')
\aThe alert (bell) character ('\u0007')
\eThe escape character ('\u001B')
\cxThe control character corresponding to x
 
Character classes
[abc]
a
, 
b
,
or 
c
 (simple class)
[^abc]
Any character except 
a
, 
b
,
or 
c
 (negation)
[a-zA-Z]
a
 through 
z
 or 
A
 through 
Z
,
inclusive (range)
[a-d[m-p]]
a
 through 
d
,
or 
m
 through 
p
: 
[a-dm-p]
 (union)
[a-z&&[def]]
d
, 
e
,
or 
f
 (intersection)
[a-z&&[^bc]]
a
 through 
z
,
except for 
b
 and 
c
: 
[ad-z]
 (subtraction)
[a-z&&[^m-p]]
a
 through 
z
,
and not 
m
 through 
p
: 
[a-lq-z]
(subtraction)
 
Predefined character classes
.Any character (may or may not match line terminators)
\dA digit: [0-9]
\DA non-digit: [^0-9]
\hA horizontal whitespace character: [ \t\xA0\u1680\u180e\u2000-\u200a\u202f\u205f\u3000]
\HA non-horizontal whitespace character: [^\h]
\sA whitespace character: [ \t\n\x0B\f\r]
\SA non-whitespace character: [^\s]
\vA vertical whitespace character: [\n\x0B\f\r\x85\u2028\u2029]
\VA non-vertical whitespace character: [^\v]
\wA word character: [a-zA-Z_0-9]
\WA non-word character: [^\w]
 
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]
 
java.lang.Character classes (simple java character type)
\p{javaLowerCase}Equivalent to java.lang.Character.isLowerCase()
\p{javaUpperCase}Equivalent to java.lang.Character.isUpperCase()
\p{javaWhitespace}Equivalent to java.lang.Character.isWhitespace()
\p{javaMirrored}Equivalent to java.lang.Character.isMirrored()
 
Classes for Unicode scripts, blocks, categories and binary properties
\p{IsLatin}
A Latin script character (script)
\p{InGreek}
A character in the Greek block (block)
\p{Lu}
An uppercase letter (category)
\p{IsAlphabetic}
An alphabetic character (binary property)
\p{Sc}
A currency symbol
\P{InGreek}
Any character except one in the Greek block (negation)
[\p{L}&&[^\p{Lu}]]
Any letter except an uppercase letter (subtraction)
 
Boundary matchers
^The beginning of a line
$The end of a line
\bA word boundary
\BA non-word boundary
\AThe beginning of the input
\GThe end of the previous match
\ZThe end of the input but for the final terminator, if any
\zThe end of the input
 
Linebreak matcher
\RAny Unicode linebreak sequence, is equivalent to \u000D\u000A|[\u000A\u000B\u000C\u000D\u0085\u2028\u2029]
 
Greedy quantifiers
X?X, once or not at all
X*X, zero or more times
X+X, one or more times
X{n}X, exactly n times
X{n,}X, at least n times
X{n,m}X, at least n but not more than m times
 
Reluctant quantifiers
X??X, once or not at all
X*?X, zero or more times
X+?X, one or more times
X{n}?X, exactly n times
X{n,}?X, at least n times
X{n,m}?X, at least n but not more than m times
 
Possessive quantifiers
X?+X, once or not at all
X*+X, zero or more times
X++X, one or more times
X{n}+X, exactly n times
X{n,}+X, at least n times
X{n,m}+X, at least n but not more than m times
 
Logical operators
XYX followed by Y
X|YEither X or Y
(X)X, as a capturing group
 
Back references
\nWhatever the nth capturing group matched
\k<name>Whatever the named-capturing group "name" matched
 
Quotation
\Nothing, but quotes the following character
\QNothing, but quotes all characters until \E
\ENothing, but ends quoting started by \Q
 
Special constructs (named-capturing and non-capturing)
(?<name>X)X, as a named-capturing group
(?:X)X, as a non-capturing group
(?idmsuxU-idmsuxU) Nothing, but turns match flags i d m s u x U on
- off
(?idmsux-idmsux:X)  X, as a non-capturing group with the given flags i d m s u x on
- off
(?=X)X, via zero-width positive lookahead
(?!X)X, via zero-width negative lookahead
(?<=X)X, via zero-width positive lookbehind
(?<!X)X, via zero-width negative lookbehind
(?>X)X, as an independent, non-capturing group
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