SecondsAndMinutes.java

package com.company;

public class Main {

    private static final String INVALID_MESSAGE = "Invalid value";

    public static void main(String[] args) {
        System.out.println("Seconds And Minutes Challenge");

        System.out.println(getDurationString(65, 45));
        System.out.println(getDurationString(3945L));

    }

    private static String getDurationString (long minutes, long seconds) {

        if ((seconds < 0) || (minutes < 0) || (seconds > 59)) {
            return INVALID_MESSAGE;
        }



        long hours = minutes / 60;
        long remainingMinutes = minutes % 60;

        String hoursString = hours + "h";

        if (hours < 10) {
            hoursString = "0" + hoursString;
        }

        String minutesString = remainingMinutes + "m";
        if (remainingMinutes < 10) {
            minutesString = "0" + minutesString;
        }

        String secondsString = seconds + "s";

        if (seconds < 10) {
            secondsString = "0" + secondsString;
        }

        return hoursString + " " + minutesString + " " + secondsString;
    }

    private static String getDurationString (long seconds) {

        if (seconds < 0) {
            return INVALID_MESSAGE;
        }

        long minutes = seconds / 60;
        long remainingSeconds = seconds % 60;

        return getDurationString(minutes,remainingSeconds);
    }
}