Java에서 아래와 같은 구문으로 이용한다.

Pattern p = Pattern.compile("^REGULAR_EXPRESSION$");
Matcher m = p.matcher(STRING);
boolean b = m.matches();

https://docs.oracle.com/javase/7/docs/api/java/util/regex/Pattern.html

Pattern.CASE_INSENSITIVE    (?i)
Pattern.COMMENTS            (?x)
Pattern.MULTILINE           (?m)
Pattern.DOTALL              (?s)
Pattern.LITERAL             None
Pattern.UNICODE_CASE        (?u)
Pattern.UNIX_LINES          (?d)

^(02|0[3-6]{1}[1-5]{1})-?[0-9]{3,4}-?[0-9]{4}$ //지역번호-xxx(x)-xxxx
^(15(44|77|88|99)|1644)-?[0-9]{4}$ //15xx/1644-xxxx

String str = "(int a, int b)";

Pattern p = Pattern.compile("\\((.*?)\\)");
Matcher m = p.matcher(str);

while(m.find())
	System.out.println(m.group(1));