Java 时钟

package com.lovo;

import java.util.Calendar;

/**
 * 时钟类
 *
 */
public class Clock {
    private int hour;            // 时
    private int minute;            // 分
    private int second;            // 秒
    
    /**
     * 构造器
     */
    public Clock() {
        Calendar cal = Calendar.getInstance();
        hour = cal.get(11);
        minute = cal.get(12);
        second = cal.get(13);
    }
    
    /**
     * 走字
     */
    public void go() {
        second++;
        if(second == 60) {
            second = 0;
            minute++;
            if(minute == 60) {
                minute = 0;
                hour++;
                if(hour == 24) {
                    hour = 0;
                }
            }
        }
    }
    
    /**
     * 显示时间
     * @return 当前时间的字符串
     */
    public String showTime() {
        String time = "";
        if(hour < 10) {
            time += "0";
        }
        time += hour + ":";
        if(minute < 10) {
            time += "0";
        }
        time += minute + ":";
        if(second < 10) {
            time += "0";
        }
        time += second;
        return time;
    }
}

1.定义时钟为类 时，分，秒为属性，时针走动和时间显示为行为，建出00:00:00显示的格式