import java.util.regex.Matcher; import java.util.regex.Pattern; /* Name of the class has to be "Main" only if the class is public. */ class Ideone { public static void main (String[] args) throws java.lang.Exception { final String regex = "\\[]*(\\[[^\\]]*\\])?>"; final String string = ""; final String subst = ""; final Pattern pattern = Pattern.compile(regex); final Matcher matcher = pattern.matcher(string); // The substituted value will be contained in the result variable final String result = matcher.replaceAll(subst); System.out.println("Substitution result: " + result); } }