java中Calendar类

1.测试代码：

package com;

import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.Date;

/**
 * Created by huyanxia on 2017/9/30.
 */
public class calendarTest {
    public static void main(String[] args) {
        Calendar calendar = Calendar.getInstance();
        Date date = new Date();
        calendar.setTime(date);
        int day = calendar.get(Calendar.DAY_OF_YEAR);
        int month = calendar.get(Calendar.DAY_OF_MONTH);
        int second = calendar.get(Calendar.SECOND);
        int maxdays = calendar.getActualMaximum(Calendar.DAY_OF_YEAR);
        int mindays = calendar.getActualMinimum(Calendar.DAY_OF_YEAR);
        int maxmonths = calendar.getActualMaximum(Calendar.DAY_OF_MONTH);
        int minmonths = calendar.getActualMinimum(Calendar.DAY_OF_MONTH);
        //int day = calendar.get(Calendar.DAY_OF_YEAR);
        SimpleDateFormat simpleDateFormat = new SimpleDateFormat("YYYY-MM-dd-HH-mm-ss");
        System.out.println("现在时间"+simpleDateFormat.format(date));
        System.out.println("今天是2017年的第几天："+day);
        System.out.println("今天是2017年的9月第几天："+month);
        System.out.println("当前的秒数："+second);
        System.out.println("今年天数最大值："+maxdays);
        System.out.println("今年天数最小值："+mindays);
        System.out.println("月份最大值："+maxmonths);
        System.out.println("月份最小值："+minmonths);
    }
}

结果：

注意：格式化时，年月日时分秒：“YYYY-MM-dd-HH-mm-ss”（24小时制）

“YYYY-MM-dd-hh-mm-ss”（12小时制）