Java RegEx replace all characters in string except for a word

Question

I am using the code in Java:

String word = "hithere";
String str = "123hithere12345hi";
output(str.replaceAll("(?!"+word+")", "x"));

However, rather than outputting: xxxhitherexxxxxxx like I want it to, it outputs: x1x2x3hxixtxhxexrxex1x2x3x4x5xhxix x , I've tried a load of different regex patterns to try to do this, but I can't seem to figure out how to do this :(
Any help would be much appreciated.

Answer 1

Well this technically works. Using only replace all and only one line, and it's assuming you string does not contain a deprecated ASCII character (BEL)

String string = "hithere";
String string2 = "asdfasdfasdfasdfhithereasasdf";
System.out.println(string2.replaceAll(string,"" + (char)string.length()).replaceAll("[^" + (char)string.length() + "]", "x").replaceAll("" + (char)string.length(), string));

Answer 2

I think this is what you're looking for, if I'm not mistaken:

String pattern = "(\\d)|(hi$)";
System.out.println("123hithere12345hi".replaceAll(pattern, "X"));

The pattern replaces any numeric digits and the word "hi".

Answer 3

This lookaround based code will work for you:

String word = "hithere";
String string = "123hithere12345hi";
System.out.println(string.replaceAll(
               ".(?=.*?\\Q" + word + "\\E)|(?<=\\Q" + word + "\\E(.){0,99}).", "x"));
//=> xxxhitherexxxxxxx