String.replaceAll () compiles the regular expression each time it is called.

   public String replaceAll(String regex, String replacement) {
        return Pattern.compile(regex).matcher(this).replaceAll(replacement);
    }

It is suggested in javadoc that it is efficient to reuse the pattern, so I modified it accordingly.

If a pattern is to be used multiple times, compiling it once and reusing it will be more efficient than invoking this method each time.