java - Convert string to lower case except all metacharacters -

i want convert a string (basically regex itself) lowercase want exclude metacharacters getting converted.

e.g. :

if

string x = "[\\s\\s]*test message indicator: (.*)[\\s\\s]*"; x = x.tolowercase(); 

it convert capital s in \\s s change meaning of regex.

i want avoid that.

final regex should [\\s\\s]*test message indicator: (.*)[\\s\\s]*.

is there way can easily?

you can use placeholder (that know not in input string) swap in , out uppercase predefined character classes of regular expression. example, replace unicode values 00a0, 00a1, 00a2 \s, \d, , \w respectively (or whichever char values anticipate never see), lower case string, , back-replace special chars:

string x = "[\\s\\s]*test message indicator: (.*)[\\s\\s]*"; x = x.replaceall("\\\\s", "\u00a0").replaceall("\\\\d","\u00a1").replaceall("\\\\w","\u00a2");; x = x.tolowercase(); x = x.replaceall("\u00a0", "\\\\s").replaceall("\u00a1","\\\\d").replaceall("\u00a2","\\\\w");; system.out.println(x); 

granted accounts few common uppercase character classes (and inefficient depending upon context) - need consult the api if regular expressions complex , need account possible uppercase regular expression values.