问题描述
0/5 14,18,3-39,52 * ? JAN,MAR,SEP MON-FRI 2002-2010
而且我有一个用于解析 Java 的 cron 表达式的正则表达式：
^([\d,\-\*\/]*\s+){3}([(LW)\d,\-\*\?\/]+\s+)([(JAN|FEB|MAR|APR|MAY|JUN|JUL|AUG|SEP|OCT|NOV|DEC)\d\,\-\*\?\/\#]+\s+)([(SUN|MON|TUE|WED|THU|FRI|SAT)\(LW)\d,\-\*\?\/\#]+\s*)([\d,\-\*\/\#]+){0,1}$
它几乎可以正常工作，但是有一个问题。如果我为任何单词添加一个额外的字母（例如：'JAAAN'），它也会解析这个 cron 表达式。 我需要帮助。我如何解决它以仅解析所有组合中的特定单词（如所列），例如“JAN”或“FEB”，但不解析“JANU”或“FEBR”。
拜托，我需要帮助！
解决方法
你没有提供足够的数据，所以它不会很漂亮：
^([\d,*\/-]*\s+){3}(\(LW\)|[\d,*?\/-]+)\s+((?:JAN|FEB|MAR|APR|MAY|JUN|JUL|AUG|SEP|OCT|NOV|DEC|[\d,*?\/#-]+)(?:\s*,\s*(?:JAN|FEB|MAR|APR|MAY|JUN|JUL|AUG|SEP|OCT|NOV|DEC|[\d,*?\/#-]+))*)\s*((?:SUN|MON|TUE|WED|THU|FRI|SAT|\(LW\)|[\d*?\/#-]+)(?:\s*(?:SUN|MON|TUE|WED|THU|FRI|SAT|\(LW\)|[\d*?\/#-]+))*)([\d,*\/#-]*)$
说明
--------------------------------------------------------------------------------
^ the beginning of the string
--------------------------------------------------------------------------------
( group and capture to \1 (3 times):
--------------------------------------------------------------------------------
[\d,*\/-]* any character of: digits (0-9),','*','\/','-' (0 or more times
(matching the most amount possible))
--------------------------------------------------------------------------------
\s+ whitespace (\n,\r,\t,\f,and " ") (1
or more times (matching the most amount
possible))
--------------------------------------------------------------------------------
){3} end of \1 (NOTE: because you are using a
quantifier on this capture,only the LAST
repetition of the captured pattern will be
stored in \1)
--------------------------------------------------------------------------------
( group and capture to \2:
--------------------------------------------------------------------------------
\( '('
--------------------------------------------------------------------------------
LW 'LW'
--------------------------------------------------------------------------------
\) ')'
--------------------------------------------------------------------------------
| OR
--------------------------------------------------------------------------------
[\d,*?\/-]+ any character of: digits (0-9),'?','-' (1 or more times
(matching the most amount possible))
--------------------------------------------------------------------------------
) end of \2
--------------------------------------------------------------------------------
\s+ whitespace (\n,and " ") (1 or
more times (matching the most amount
possible))
--------------------------------------------------------------------------------
( group and capture to \3:
--------------------------------------------------------------------------------
(?: group,but do not capture:
--------------------------------------------------------------------------------
JAN 'JAN'
--------------------------------------------------------------------------------
| OR
--------------------------------------------------------------------------------
FEB 'FEB'
--------------------------------------------------------------------------------
| OR
--------------------------------------------------------------------------------
MAR 'MAR'
--------------------------------------------------------------------------------
| OR
--------------------------------------------------------------------------------
APR 'APR'
--------------------------------------------------------------------------------
| OR
--------------------------------------------------------------------------------
MAY 'MAY'
--------------------------------------------------------------------------------
| OR
--------------------------------------------------------------------------------
JUN 'JUN'
--------------------------------------------------------------------------------
| OR
--------------------------------------------------------------------------------
JUL 'JUL'
--------------------------------------------------------------------------------
| OR
--------------------------------------------------------------------------------
AUG 'AUG'
--------------------------------------------------------------------------------
| OR
--------------------------------------------------------------------------------
SEP 'SEP'
--------------------------------------------------------------------------------
| OR
--------------------------------------------------------------------------------
OCT 'OCT'
--------------------------------------------------------------------------------
| OR
--------------------------------------------------------------------------------
NOV 'NOV'
--------------------------------------------------------------------------------
| OR
--------------------------------------------------------------------------------
DEC 'DEC'
--------------------------------------------------------------------------------
| OR
--------------------------------------------------------------------------------
[\d,*?\/#-]+ any character of: digits (0-9),'#','-' (1 or more
times (matching the most amount
possible))
--------------------------------------------------------------------------------
) end of grouping
--------------------------------------------------------------------------------
(?: group,but do not capture (0 or more
times (matching the most amount
possible)):
--------------------------------------------------------------------------------
\s* whitespace (\n,and " ")
(0 or more times (matching the most
amount possible))
--------------------------------------------------------------------------------,'
--------------------------------------------------------------------------------
\s* whitespace (\n,and " ")
(0 or more times (matching the most
amount possible))
--------------------------------------------------------------------------------
(?: group,but do not capture:
--------------------------------------------------------------------------------
JAN 'JAN'
--------------------------------------------------------------------------------
| OR
--------------------------------------------------------------------------------
FEB 'FEB'
--------------------------------------------------------------------------------
| OR
--------------------------------------------------------------------------------
MAR 'MAR'
--------------------------------------------------------------------------------
| OR
--------------------------------------------------------------------------------
APR 'APR'
--------------------------------------------------------------------------------
| OR
--------------------------------------------------------------------------------
MAY 'MAY'
--------------------------------------------------------------------------------
| OR
--------------------------------------------------------------------------------
JUN 'JUN'
--------------------------------------------------------------------------------
| OR
--------------------------------------------------------------------------------
JUL 'JUL'
--------------------------------------------------------------------------------
| OR
--------------------------------------------------------------------------------
AUG 'AUG'
--------------------------------------------------------------------------------
| OR
--------------------------------------------------------------------------------
SEP 'SEP'
--------------------------------------------------------------------------------
| OR
--------------------------------------------------------------------------------
OCT 'OCT'
--------------------------------------------------------------------------------
| OR
--------------------------------------------------------------------------------
NOV 'NOV'
--------------------------------------------------------------------------------
| OR
--------------------------------------------------------------------------------
DEC 'DEC'
--------------------------------------------------------------------------------
| OR
--------------------------------------------------------------------------------
[\d,'-' (1 or more
times (matching the most amount
possible))
--------------------------------------------------------------------------------
) end of grouping
--------------------------------------------------------------------------------
)* end of grouping
--------------------------------------------------------------------------------
) end of \3
--------------------------------------------------------------------------------
\s* whitespace (\n,and " ") (0 or
more times (matching the most amount
possible))
--------------------------------------------------------------------------------
( group and capture to \4:
--------------------------------------------------------------------------------
(?: group,but do not capture:
--------------------------------------------------------------------------------
SUN 'SUN'
--------------------------------------------------------------------------------
| OR
--------------------------------------------------------------------------------
MON 'MON'
--------------------------------------------------------------------------------
| OR
--------------------------------------------------------------------------------
TUE 'TUE'
--------------------------------------------------------------------------------
| OR
--------------------------------------------------------------------------------
WED 'WED'
--------------------------------------------------------------------------------
| OR
--------------------------------------------------------------------------------
THU 'THU'
--------------------------------------------------------------------------------
| OR
--------------------------------------------------------------------------------
FRI 'FRI'
--------------------------------------------------------------------------------
| OR
--------------------------------------------------------------------------------
SAT 'SAT'
--------------------------------------------------------------------------------
| OR
--------------------------------------------------------------------------------
\( '('
--------------------------------------------------------------------------------
LW 'LW'
--------------------------------------------------------------------------------
\) ')'
--------------------------------------------------------------------------------
| OR
--------------------------------------------------------------------------------
[\d*?\/#-]+ any character of: digits (0-9),'-' (1 or more times
(matching the most amount possible))
--------------------------------------------------------------------------------
) end of grouping
--------------------------------------------------------------------------------
(?: group,but do not capture:
--------------------------------------------------------------------------------
SUN 'SUN'
--------------------------------------------------------------------------------
| OR
--------------------------------------------------------------------------------
MON 'MON'
--------------------------------------------------------------------------------
| OR
--------------------------------------------------------------------------------
TUE 'TUE'
--------------------------------------------------------------------------------
| OR
--------------------------------------------------------------------------------
WED 'WED'
--------------------------------------------------------------------------------
| OR
--------------------------------------------------------------------------------
THU 'THU'
--------------------------------------------------------------------------------
| OR
--------------------------------------------------------------------------------
FRI 'FRI'
--------------------------------------------------------------------------------
| OR
--------------------------------------------------------------------------------
SAT 'SAT'
--------------------------------------------------------------------------------
| OR
--------------------------------------------------------------------------------
\( '('
--------------------------------------------------------------------------------
LW 'LW'
--------------------------------------------------------------------------------
\) ')'
--------------------------------------------------------------------------------
| OR
--------------------------------------------------------------------------------
[\d*?\/#-]+ any character of: digits (0-9),'-' (1 or more times
(matching the most amount possible))
--------------------------------------------------------------------------------
) end of grouping
--------------------------------------------------------------------------------
)* end of grouping
--------------------------------------------------------------------------------
) end of \4
--------------------------------------------------------------------------------
( group and capture to \5:
--------------------------------------------------------------------------------
[\d,*\/#-]* any character of: digits (0-9),'-' (0 or more times
(matching the most amount possible))
--------------------------------------------------------------------------------
) end of \5
--------------------------------------------------------------------------------
$ before an optional \n,and the end of the
string