Java 正则表达式 - 否则条件

Question

I have two strings.

String str1 = "\"password\":\"123456\", \"code\":\"434343\"";

I want to convert str1 to "\"password\":\"******\", \"code\":\"434343\""

String str2 = "\"password\":null, \"code\":\"434343\"";

and str2 to "\"password\":null, \"code\":\"434343\""

I have to do this with only one regex. I read that Java does not support conditions in the regex. But I see things like (?(?=regex)then|else)

I also tried so many things such that:

((?<=(?i)(password\"\\s*:\\s*\"*)).+?(?=\\",))|((?<!(password\"\\s*:\\s*))\\d+)

I use replaceAll() function with replacement parameter: "$1******"

If there is a "password":" , the value till \", should be asterisks. Otherwise, it remains as it is.

I failed. Can anyone help me?

Answer 1

If your starting string be a fragment from JSON, then you should parse it, and replace the password field with some masked version. If you must use regex, I suggest keeping it simple and using:

String str1 = "\"password\":\"123456\", \"code\":\"434343\"";
String output = str1.replaceAll("\"password\":\".*?\"", "\"password\":\"*****\"");
System.out.println(output);  // "password":"*****", "code":"434343"

I suggest not displaying the original password with every character replaced with an asterisk. The reason for this is that it still gives away the original password's length, and therefore is not really fully masked.