Question

I have a simple regex :

String expr = "#^" + STARTER + "[.]" + ENDER + "$#";
c = c.replaceAll(expr, STARTER + REPLACEMENT + ENDER);

Result :

A string which contains

STARTER an exemple ENDER 

matches but :

STARTER an (exemple) ENDER

doesn’t match.

Why are the characters ), ( and $ excluded from the . regex class?
How can I make it accept any character?

Answer 1

Assuming that STARTER and ENDER are supposed to be literal strings, not regexes themselves, and that your goal is to match a string that starts with STARTER, ends with ENDER and may contain anything (except newlines) in-between, you could use

String expr = "^" + Pattern.quote(STARTER) + ".*" + Pattern.quote(ENDER) + "$";

This means that there can be only one match per string.

So, if STARTER == "Start", ENDER == "End" and REPLACEMENT == "Replace", the replaceAll() call would do the following:

"Start foobar End"      --> "StartReplaceEnd"
"StartEnd"              --> "StartReplaceEnd"
" Start foobar End"     --> " Start foobar End"
"Start foo\nbar End"    --> "Start foo\nbar End"
"foo Start bar End baz" --> "foo Start bar End baz"
"Start End\nStart End"  --> "Start End\nStart End"

Since this doesn’t make much sense, you might want to explain what your actual goal for this regex is.