java - A "Nice" way to get substring between an opening and a matching closing tag (parantheses etc.) -

i quite run task of extracting substring string located between opening tag (such "(") , closing tag (for example ")"), such "level" of opening tag matches "level" of closing tag.

for example, in following string,

((a + (b * c) + d) + e) 

when given index 1 (pointing second opening tag "(" in string), interested in substring

(a + (b * c) + d) 

i'm not interested in part until first closing tag:

(a + (b * c) 

in addition one-character tags, longer strings (e.g., "begin", "end") should work, too. not hard solve this, find running through string in loop quite ugly, possibly inefficient , error-prone.

is there nice way this?

(maybe there regex hack? won't work directly due need of counting.)

i've had similar this, using < , > instead.

the best way in opinion iterate string, , keep stack of 'open' , 'close' tags go along. when hit point number of open , close tags same, know you've found substring. method require recursion/loops once parsed outermost case still have inner cases.

alternatively, same, hit close tag, parse substring of last open tag , close tag. method harder keep track of strings immutable.

if want code examples can provide them, string parsing pretty fun learn