Duration.java

import java.text.DecimalFormat;

public class Duration {
    private int hours;
    private int minutes;
    private int seconds;

    public static void main(String[] args) {
        //TEST HARNESS
        Duration d1 = new Duration();
        Duration d2 = new Duration(0,3,24);
        Duration d3 = new Duration("00:03:45");
        Duration d4 = new Duration("00:03:20");
        d2.getTotal();
        d2.getSeconds();
        d2.getMinutes();
        d2.getHours();
        d2.toString();
        d2.add(d3);
        //100% Method coverage
    }

    //Constructor that takes integer arguments to build Duration with.
    public Duration(int hours, int minutes, int seconds) {
        this.hours = hours;
        this.minutes = minutes;
        this.seconds = seconds;
    }

    //Default Constructor for Duration
    public Duration() {
        this.hours = 0;
        this.minutes = 0;
        this.seconds = 0;
    }

    //Constructor that accepts String input and parses as Integer
    public Duration(String duration) {
        String[] time = duration.split(":");
        String stringHours = time[0];
        String stringMinutes = time[1];
        String stringSeconds = time[2];
        hours = Integer.parseInt(stringHours);
        minutes = Integer.parseInt(stringMinutes);
        seconds = Integer.parseInt(stringSeconds);
    }

    //toString method that converts a Duration object into a String object
    public String toString() {
        DecimalFormat df = new DecimalFormat("00");
        String stringHours = df.format(this.hours);
        String stringMinutes = df.format(this.minutes);
        String stringSeconds = df.format(this.seconds);
        return stringHours + ":" + stringMinutes + ":" + stringSeconds;
    }

    //Add method that accepts another Duration object as a parameter to add to the original object
    public void add(Duration d2) {
        if (seconds + d2.seconds >= 60) {
            minutes += ((seconds + d2.seconds) / 60); //Finds out the amount of extra minutes and adds that result to the minutes variable
            seconds = ((seconds + d2.seconds) % 60); //Finds out the remainder to set the new seconds
        } else {
            seconds += d2.seconds;
        }

        if (minutes + d2.minutes >= 60) {
            hours += ((minutes + d2.minutes) / 60); //Finds out the amount of extra hours and adds that result to the hours variable
            minutes = ((minutes + d2.minutes) % 60); //Finds out the remainder to set the new minutes
        } else {
            minutes += d2.minutes;
        }
        hours += d2.hours;

    }

    //Getter methods for each variable
    public int getHours() {
        return hours;
    }

    public int getMinutes() {
        return minutes;
    }

    public int getSeconds() {
        return seconds;
    }

    //The getTotal method creates a concatenated String of a Tracks attributes and is then parsed as an int
    //This is so that a comparison can be made easily
    public int getTotal() {
        //This String object tot creates a String with the int values of a Track object
        //No arithmetic is carried out as the int values are concatenated
        String tot = "" + hours + minutes + seconds;
        int total = Integer.parseInt(tot);
        //The String is parsed back to an int value to act as the final comparison value and returned as total
        return total;
    }

}