Date和 Calendar

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

import org.junit.Test;

public class DateTest {

    @Test
    public void test01() {
        Date date = new Date();
        // date.getYear()获取的是1900年开始的时间
        System.out.println(date.getYear() + 1900);
        // getMonth() 0-11
        System.out.println(date.getMonth() + 1);
        System.out.println(date.getDate()); // 一个月当中的第几天
        System.out.println(date.getDay()); // 周几
        System.out.println(date);// Mon Sep 11 14:43:19 CST 2017
        // 转换成字符串
        SimpleDateFormat sdf = new SimpleDateFormat("yyyy年-MM月-dd日 hh:mm:ss");
        // format 把日期格式转换成字符串
        System.out.println(sdf.format(date));
        try {
            date = sdf.parse("2017年-11月-09日 20:02:20");
            System.out.println(date);
        } catch (ParseException e) {
            e.printStackTrace();
        }
    }

    @Test
    public void test02() {
        // 创建日历类对象
        Calendar c = Calendar.getInstance();
        System.out.println(c.get(Calendar.YEAR));
        System.out.println(c.get(Calendar.MONTH) + 1);
        System.out.println(c.get(Calendar.DAY_OF_MONTH));
        System.out.println(c.get(Calendar.DAY_OF_WEEK) - 1);
        System.out.println(c.getTime());
        System.out.println(c.get(Calendar.HOUR_OF_DAY));
        System.out.println(c.get(Calendar.MINUTE));
        System.out.println(c.get(Calendar.SECOND));
    }

}