How to replace all characters in a Java string with stars

Question

I want to replace all the characters in a Java String with * character. So it shouldn\'t matter what character it is, it should be replaced with a *

Answer 1

How abt creating a new string with the number of * = number of last string char?

StringBuffer bf = new StringBuffer();
for (int i = 0; i < source.length(); i++ ) {
    bf.append('*');
}

Answer 2

Don't use regex at all, count the String length, and return the according number of stars.

Plain Java < 8 Version:

int len = str.length();
StringBuilder sb = new StringBuilder(len);
for(int i = =; i < len; i++){
    sb.append('*');
}
return sb.toString();

Plain Java >= 8 Version:

int len = str.length();
return IntStream.range(0, n).mapToObj(i -> "*").collect(Collectors.joining());

Using Guava:

return Strings.repeat("*", str.length());
// OR
return CharMatcher.ANY.replaceFrom(str, '*');

Using Commons / Lang:

return StringUtils.repeat("*", str.length());

Answer 3

System.out.println("foobar".replaceAll(".", "*"));