Timer.java

import java.time.LocalTime;
import java.time.format.DateTimeFormatter;

public class Timer {

    public static void main(String[] args) {

        /* Get the current time */
        LocalTime localTime = LocalTime.now();

        /* Specify the formatting for the timestamp string */
        /* Read this Java documentation link to understand! */
        /* https://docs.oracle.com/javase/8/docs/api/java/time/format/DateTimeFormatter.html */
        DateTimeFormatter dateTimeFormatter = DateTimeFormatter.ofPattern("HH:mm:ss.SS");

        /* Generate the formatted timestamp string */
        String timestamp = String.format("[%s]", dateTimeFormatter.format(localTime));

        /* Print the formatted timestamp string */
        System.out.println(timestamp);
    }
}