Example of method overloading. MyTime Class with add method and Object argument.

TimeDemo.java

/**
 * Example of method overloading
 *Create a class name MyTime as follows:
 *
 * List of data member
 * 1.	hours
 * 2.	minutes
 * 3.	seconds
 *
 * List of methods
 * 1.	setTime – to initialize data member of Time class
 * 2.	printTime – to print current time such as HH: MI : SS
 * 3.	add(int) – add number of seconds to the current object of Time class
 * 4.	add(int , int ) – add specified number of minutes as well as seconds to current object of time
 * 5.	add(Time) – to add specified object of time as an argument to the current object of time
 *
 * Try to learn and implement - DRY Principle
 * Reference: https://en.wikipedia.org/wiki/Don%27t_repeat_yourself
 *
 * */
class MyTime{
    private int hours, minutes, seconds;
    /**
     * To initialize private data member from hours, minutes and seconds
     */
    void setTime(int hours, int minutes, int seconds){
        int totalSeconds = getSecondsFrom(hours,minutes,seconds);
        initializeTimeFromSeconds(totalSeconds);
    }
    void setTime( int minutes, int seconds){
        int totalSeconds = getSecondsFrom(0,minutes,seconds);
        initializeTimeFromSeconds(totalSeconds);
    }
    void setTime(  int seconds){
        int totalSeconds = getSecondsFrom(0,0,seconds);
        initializeTimeFromSeconds(totalSeconds);
    }
    void printTime(){
        System.out.println("Hours: " + hours + " Minutes: " + minutes + " Seconds: " + seconds);
    }
    void add(int seconds){
        add(0,seconds);
    }
    void add(int minutes, int seconds){
        int totalseconds = getTimeInSeconds() + seconds + (minutes*60);
        initializeTimeFromSeconds(totalseconds);
    }
    void add(MyTime t){
       int totalSeconds = this.getTimeInSeconds()  +t.getTimeInSeconds();
       this.initializeTimeFromSeconds(totalSeconds);
    }
    private int getSecondsFrom(int hours, int minutes, int seconds){
        int result;
        result = seconds;
        result += minutes*60;
        result += hours * 3600;
        return result;
    }
    private int getSecondsFrom(int minutes, int seconds){
        return getSecondsFrom(0,minutes,seconds);
    }
    int getTimeInSeconds(){
        return  ((hours*3600) + (minutes*60) + seconds);
    }

    /**
     * @param seconds
     * To convert seconds into Hours, Minutes and Seconds
     */
    private void initializeTimeFromSeconds(int seconds){
        int totalSeconds;
        this.hours = seconds/3600;
        totalSeconds = seconds%3600;
        this.minutes = totalSeconds/60;
        this.seconds = totalSeconds%60;
    }
}
public class TimeDemo {
    public static void main(String[] args) {
        MyTime t1 = new MyTime();
        t1.setTime(1,66,3680);
        t1.printTime();

        MyTime t2= new MyTime();
        t2.setTime(0,0,40);
        t2.printTime();

        t2.add(80);
        t2.printTime();

        t1.add(t2);
        System.out.println("After t1 + t2");
        t1.printTime();
        t2.printTime();
    }
}

Sample output:

Hours: 3 Minutes: 7 Seconds: 20
Hours: 0 Minutes: 0 Seconds: 40
Hours: 0 Minutes: 2 Seconds: 0
After t1 + t2
Hours: 3 Minutes: 9 Seconds: 20
Hours: 0 Minutes: 2 Seconds: 0