how to capture parenthesized groups with java regex -

i've string :

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

and want capture parenthesized groups java regex. thought simple regex

pattern p = pattern.compile("\\((.*)\\)",pattern.dotall); 

would work not.

whats wrong that?

the language you're trying define regular expression unfortunately smells non-regular, i.e. regular expressions not suitable type of expressions. (to precise, "well balanced parenthesis" not can define regular expressions.)

if want find substring a * b in example, following expressions should do:

pattern p = pattern.compile("\\(([^()]*)\\)"); matcher m = p.matcher("(((a * b) * ) + c) * d)"); if (m.find())     system.out.println(m.group(1));   // prints "a * b"