Mask part of the String data which is of different lengths using Java

Question

I am in need to mask PII data for my application. The PII data will be of String format and of variable lengths, as it may include name, address, mail id's etc.

So i need to mask these data before logging them, it should not be a full mask instead, if the length of string is less than or equal to 8 characters then mask the first half with "XXX etc.."

If the length is more than 8 then mask the first and last portion of the string such that only the mid 5 characters are visible. I know we can do this using java sub-stringa nd iterating over the string, but want to know if there is any other simple solution to address this. Thanks in advance

Answer 1

If you are using Apache Commons, you can do like

String maskChar = "*";

//number of characters to be masked
String maskString = StringUtils.repeat( maskChar, 4);

//string to be masked
String str = "FirstName";

//this will mask first 4 characters of the string
System.out.println( StringUtils.overlay(str, maskString, 0, 4) );

You can check the string length before generating maskString using if else statement.