How to escape back slashes '\' in a Java string while ignoring all the places where '\' is used for escaping standard characters?

Question

I want to escape back slashes in a Java string. I tried to use the below code-

public static String escapeString(String str)
{
   return str.replace("\\", "\\\\");
}

This works like a charm. But, then I noticed that I also have some scenarios where the "\" character is used intentionally for escaping some standard characters like '\n', '\r', '\t' etc. Well, I don't want these '\' characters to get escaped because then these will become like '\n', '\r', '\t' which is not intended. Bellow example will make it clearer-

I/P String-

mdlhCw~pzOb@KV\Sd@c@CGK_DZiI|AuH\rdCiNrGi^xQ}HjDkFf@_IyTf@mKNm@H}C]

O/P String-

mdlhCw~pzOb@KV\Sd@c@CGK_DZiI|AuH\tdCiNrGi^xQ}HjDkFf@_IyTf@mKNm@H}C]

So, here I am escaping the '\' before 'S' but not the '\' before 't'. Other than brute force by checking for every possible scenario, is there any other way to doe that ?

Answer 1

use the String.replaceAll method, which accepts a regular expression as an input to find strings to replace.

Place a regular expression that matches all backslashes, except those that have your blacklisted character next to it.