public class ThisTest
{
    public static void main(String[] args)
    {
        SimpleTime time = new SimpleTime(15,30,19);
        System.out.println(time.buildString());
    }
}

class SimpleTime
{
    private int hour;
    private int minute;
    private int second;

    public SimpleTime(int hour,int minute,int second)
    {
        this.hour = hour;
        this.minute = minute;
        this.second = second;
    }

    public String buildString()
    {
        return String.format("%24s: %s\\n%24s: %s",
            "this.toUniversalString()", this.toUniversalString(),
            "toUniversalString()", toUniversalString());
    }

    public String toUniversalString()
    {
        return String.format("%02d:%02d:%02d",
            this.hour,this.minute,this.second);
    }
}