public final class MyTime {
    private int hour;
    private int minute;
    private int second;

    public MyTime() {
        this.hour = 0;
        this.minute = 0;
        this.second = 0;
    }

    public MyTime(int hr, int mt, int se) throws Exception {
        this.setHour(hr);
        this.setMinute(mt);
        this.setSecond(se);
    }

    public void goPerSecond() {
        this.second++;
        if (this.second == 60) {
            this.second = 0;
            this.minute++;
            if (this.minute == 60) {
                this.minute = 0;
                this.hour++;
                if (this.hour == 24) {
                    this.hour = 0;
                }
            }
        }
    }

    public int secondsBetween(MyTime atime) {
        return this.getSeconds(this) - this.getSeconds(atime);
    }

    public String toString() {
        StringBuffer retVal = new StringBuffer();
        String tmpStr = Integer.toString(this.hour);
        if (tmpStr.length() == 1) {
            retVal.append("0");
        }
        retVal.append(tmpStr);
        retVal.append("-");
        tmpStr = Integer.toString(this.minute);
        if (tmpStr.length() == 1) {
            retVal.append("0");
        }
        retVal.append(tmpStr);
        retVal.append("-");
        tmpStr = Integer.toString(this.second);
        if (tmpStr.length() == 1) {
            retVal.append("0");
        }
        retVal.append(tmpStr);
        return retVal.toString();
    }

    public int getHour() {
        return this.hour;
    }

    public void setHour(int hour) throws Exception {
        if (hour < 0 || hour > 23) {
            throw new Exception("hour < 0 || hour > 23");
        }
        this.hour = hour;
    }

    public int getMinute() {
        return this.minute;
    }

    public void setMinute(int minute) throws Exception {
        if (minute < 0 || minute > 59) {
            throw new Exception("minute < 0 || minute > 59");
        }
        this.minute = minute;
    }

    public int getSecond() {
        return this.second;
    }

    public void setSecond(int second) throws Exception {
        if (second < 0 || second > 59) {
            throw new Exception("second < 0 || second > 59");
        }
        this.second = second;
    }

    private int getSeconds(MyTime atime) {
        return atime.hour * 3600 + atime.minute * 60 + atime.second;
    }
}

public final class TestMytime {
    public static void main(String[] args) {
        try {
            MyTime myTime = new MyTime();
            myTime.setHour(12);
            myTime.setMinute(0);
            myTime.setSecond(0);
            System.out.println(myTime.toString());
            MyTime newTime = new MyTime(13, 59, 59);
            System.out.println(newTime.toString());
            newTime.goPerSecond();
            System.out.println(newTime.toString());
            System.out.println(newTime.secondsBetween(myTime));
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}

import java.util.Calendar;
public class MyTime {
    
    private int hour, minute, second;
    private static final char SEPARATOR = '-';
    
    public MyTime() { }
    
    public MyTime(int h, int m, int s) {
        hour = h;
        minute = m;
        second = s;
        if (hour > 23 || minute > 59 || second > 59) adjust();
    }
    
    public void forwardOneSecond() {
        second++;
        if (second > 59) adjust();
    }
    
    private void adjust() {  // 如果时间格式不正确,做相应调整
        minute += second / 60;
        second %= 60;
        hour += minute / 60;
        minute %= 60;
        hour %= 24;
    }
    
    public long offsetByNow() {
        Calendar myTime = Calendar.getInstance();
        Calendar now = Calendar.getInstance();
        myTime.set(now.get(Calendar.YEAR), now.get(Calendar.MONTH), now.get(Calendar.DATE), hour, minute, second);
        return (myTime.getTimeInMillis() - now.getTimeInMillis()) / 1000;
    }
    
    public String toString() {
        return (hour<10?"0":"") + hour + SEPARATOR
            + (minute<10?"0":"") + minute + SEPARATOR
            + (second<10?"0":"") + second;
    }

    // 测试程序
    public static void main(String[] args) {
        MyTime myTime = new MyTime(13, 30, 8);
        System.out.println(myTime);
        myTime.forwardOneSecond();
        System.out.println("前进一秒后：" + myTime);
        System.out.println("与当前时间之差（秒）：" + myTime.offsetByNow());
    }

}