The LoggerHelper class will scramble the logs.

LoggerHelper.scala

package com.knoldus

class LoggerHelper {
    private val regex = "\\b\\d{1,3}\\.\\d{1,3}\\.\\d{1,3}\\.\\d{1,3}\\b"
    private val password = "Password: "
    private val userName = "UserName: "

    def scramble(message : String) = scrambleUsername(scrambleIp((scramblePassword(message))))

    private def scrambleUsername(message : String) = {
        if(message.contains(userName)) {
            val index = message.indexOf(userName) + userName.length()
            val textStartedPassword = message.substring(index)
            message.substring(0, index) + "X" + textStartedPassword.substring(textStartedPassword.indexOf(" "))
        }
        else {
            message
        }
    }

    private def scrambleIp(message : String) = message.replaceAll(regex, "XXX.XXX.XXX.XXX")

    private def scramblePassword(message : String) = {
        if(message.contains(password)) {
            val index = message.indexOf(password) + password.length()
            val textStartedPassword = message.substring(index)
            message.substring(0, index) + "X" + textStartedPassword.substring(textStartedPassword.indexOf(" "))
        }
        else {
            message
        }
    }
}