CalendarDemo2~4 对时间获取及设置操作

/**

*    Calendar提供了可以针对不同时间分量（时间单位）

*    单独设置值的相关方法

*    void set(int field,int value)

*     对指定的时间分量设置指定的值

*/

public class CalendarDemo2 {
    public static void main(String[] args) {
        Calendar calendar = Calendar.getInstance();
        System.out.println(calendar);

        calendar.set(Calendar.YEAR, 2008);
        System.out.println(calendar.getTime());
        calendar.set(Calendar.MONTH, Calendar.AUGUST);
        System.out.println(calendar.getTime());
        /*
         * 设置日
         */
        calendar.set(Calendar.DAY_OF_MONTH, 8);
        System.out.println(calendar.getTime());
        calendar.set(Calendar.HOUR_OF_DAY, 20);
        calendar.set(Calendar.MINUTE, 8);
        calendar.set(Calendar.SECOND, 8);
        System.out.println(calendar.getTime());

        calendar.set(Calendar.DAY_OF_WEEK,Calendar.MONDAY);
        System.out.println(calendar.getTime());

//        calendar.set(2008, 7, 8);
//        System.out.println(calendar.getTime());

        Date date = calendar.getTime();
        SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH点mm分ss秒");
        String dateStr = sdf.format(date);
        System.out.println(dateStr);

    }
}

/**

*    获取某一个时间分量所对应的值：

*int get （int field）

*

*/

public class CalendarDemo3 {
    public static void main(String[] args) {
        Calendar calendar = Calendar.getInstance();

        int year = calendar.get(Calendar.YEAR);
        int month = calendar.get(Calendar.MONTH)+1;
        int days = calendar.get(Calendar.DATE);

        int hour = calendar.get(Calendar.HOUR_OF_DAY);
        int minute = calendar.get(Calendar.MINUTE);
        int sec = calendar.get(Calendar.SECOND);

        System.out.println(year+"年"+""+month+"月"+days+"日"+hour+"时"+minute+"分"+sec+"秒");
        int weekday = calendar.get(Calendar.DAY_OF_WEEK);
        String[] week = {"星期日","星期一","星期二","星期三","星期四","星期五","星期六"};
        System.out.println(week[weekday-1]);

        int max = calendar.getActualMaximum(Calendar.DAY_OF_MONTH);
        System.out.println("当月有"+max+"天");
        int maxOfYear = calendar.getActualMaximum(Calendar.DAY_OF_YEAR);
        System.out.println("当年有"+maxOfYear+"天");
    }
}

/**

*    void add(int field,int value)

* 给定的时间分量累加给定的值，若value是负数，则是做减法操作

*/

public class CalendarDemo4 {
    public static void main(String[] args) {
        Calendar calendar = Calendar.getInstance();

        calendar.add(Calendar.YEAR, 3);
        calendar.add(Calendar.MONTH, 2);
        calendar.add(Calendar.DAY_OF_YEAR, 25);
        calendar.add(Calendar.DAY_OF_YEAR, -3);
        System.out.println(calendar.getTime());
        Date date = calendar.getTime();
        SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
        String str = sdf.format(date);
        System.out.println(str);
    }
}