String.replaceAll is considerably slower than doing the job yourself

Question

I have an old piece of code that performs find and replace of tokens within a string.

It receives a map of from and to pairs, iterates over

Answer 1

replace and replaceAll uses regex internally which in most cases gives a serious performance impact compared to e.g., StringUtils.replace(..).

String.replaceAll():

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

String.replace() uses Pattern.compile underneath.

public String replace(CharSequence target, CharSequence replacement) {
  return Pattern.compile(target.toString(), Pattern.LITERAL)
         .matcher(this ).replaceAll(
           Matcher.quoteReplacement(replacement.toString()));
}

Also see Replace all occurrences of substring in a string - which is more efficient in Java?