java-正则表达式拆分包含多个组的字符串

Question

I need to split this string

(2005)[1]1,2,3,4[2]1(2008)[2]2–;3,4(2009)[3]1,2,3-4(2010)[4]1,2,3-4(2011)[5]1(2012)[5]2,3-4[6]1,2\[\](2014)[6]3-4[7]1-2(2015)[7]3-4[8]1-2(2016)[10]1[8]3-4[9]1-2,3-4(2017)[10]2

As:

1, "1,2,3,4"  
2, 1 2
2, 2–;3,4

For the input "(2005)[1]1,2,3,4" I need value in [ ] in capture group 1 and the rest of the string (1,2,3,4) in capture group 2 and repeat for the entire string

I have created this regex string but it is not working as intended

\[(.*?)\](.+?)(?=\[|\(|$)

Please see my regex implementation

The problem is when there is nothing after [] it is capturing (year) which it should not do

Answer 1

The (.+?)(?=\\[|\\(|$) part of the pattern matches any 1 or more chars other than a newline up to the leftmost [ , ( or end of string. You need to allow matching zero or more chars here.

However, a [^\\[(] negated character class here will be more efficient and elegant:

\[(.*?)\]([^\[(]*)

See this regex demo .

Or a bit more efficient,

\[([^\]\[]*)\]([^\[(]*)

See another regex demo .

Details

• \\[ - a [
• ([^\\]\\[]*) - Group 1: any 0+ chars other than [ and ]
• \\] - a ]
• ([^\\[(]*) - Group 2: any 0+ chars other than [ and ( .