jdk8_dateApi

package com.zhangwl.pg0924;

import org.junit.Test;

import javax.swing.text.DateFormatter;
import java.sql.Date;
import java.text.DateFormat;
import java.time.*;
import java.time.format.DateTimeFormatter;
import java.time.temporal.ChronoUnit;

/**
 * @ClassName DateApiDemo
 * @Description
 * @Author zhangwl
 * @Date 2019/9/24 22:43
 * @Version 1.0
 **/
public class DateApiDemo {

    /*日期*/
    @Test
    public void test_local_date() {
        LocalDate nowDate = LocalDate.now();
        System.out.println("今天的日期：" + nowDate);
        int year = nowDate.getYear();
        System.out.println("年：" + year);
        int month = nowDate.getMonthValue();
        System.out.println("月：" + month);
        int day = nowDate.getDayOfMonth();
        System.out.println("日：" + day);
    }

    /*时间*/
    @Test
    public void test_local_time() {
        LocalTime nowTime = LocalTime.now();
        System.out.println("现在的时间：" + nowTime);
        int hour = nowTime.getHour();
        System.out.println("时：" + hour);
        int minute = nowTime.getMinute();
        System.out.println("分：" + minute);
        int second = nowTime.getSecond();
        System.out.println("秒：" + second);
        int nano = nowTime.getNano();
        System.out.println("毫秒：" + nano);
    }

    /*日期时间*/
    @Test
    public void test_local_date_time() {
        LocalDateTime nowDateTime = LocalDateTime.now();
        System.out.println("今天日期时间：" + nowDateTime);
        System.out.println("年：" + nowDateTime.getYear());
        System.out.println("月：" + nowDateTime.getMonthValue());
        System.out.println("日：" + nowDateTime.getDayOfMonth());
        System.out.println("**********************************");
        System.out.println("时：" + nowDateTime.getHour());
        System.out.println("分：" + nowDateTime.getMinute());
        System.out.println("秒：" + nowDateTime.getSecond());
        System.out.println("毫秒：" + nowDateTime.getNano());
    }

    /*获取指定日期的日期*/
    @Test
    public void test_cust_local_date() {
        LocalDate localDate = LocalDate.of(1991, 10, 12);
        System.out.println(LocalDate.ofYearDay(1991, localDate.getDayOfYear()));
        System.out.println(LocalDate.ofEpochDay(localDate.toEpochDay()));//参数为距离1970-01-01的天数
        System.out.println("*******************************************");
        System.out.println(LocalDate.parse("1991-10-12"));
        System.out.println(LocalDate.parse("19911012", DateTimeFormatter.ofPattern("yyyyMMdd")));
    }

    @Test
    public void test_cust_local_time() {
        System.out.println(LocalTime.of(8, 20));
        System.out.println(LocalTime.of(8, 20, 30));
        System.out.println(LocalTime.of(8, 20, 30, 40));
        System.out.println("*************************************************************");
        LocalTime tTime = LocalTime.of(8, 20, 30, 40);
        System.out.println(LocalTime.ofSecondOfDay(tTime.toSecondOfDay()));//参数为距离当天零时的秒数
        System.out.println(LocalTime.ofNanoOfDay(tTime.toNanoOfDay()));
        System.out.println("*************************************************************");
        System.out.println(LocalTime.parse("08:20:30"));
        System.out.println(LocalTime.parse("082030", DateTimeFormatter.ofPattern("HHmmss")));
    }

    @Test
    public void test_cust_local_date_time() {
        System.out.println(LocalDateTime.of(1991, 10, 12, 8, 20, 30));
        System.out.println(LocalDateTime.of(1991, Month.OCTOBER, 8, 20, 30, 150));
        System.out.println(LocalDateTime.parse("1991-10-12 08:20:30", DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss")));
    }

    /*日期的比较*/
    @Test
    public void test_comp_local_date() {
        LocalDate myDate = LocalDate.of(1991, 10, 12);
        LocalDate nowDate = LocalDate.now();
        /*比较两个日期*/
//        System.out.println("今天是1991-10-12吗?" + nowDate.equals(myDate));
//        System.out.println(myDate + "是否在" + nowDate + "之前？=>" + myDate.isBefore(nowDate));
//        System.out.println(myDate + "是否在" + nowDate + "之后？=>" + myDate.isAfter(nowDate));

        MonthDay nowDay = MonthDay.from(nowDate);
        MonthDay myDay = MonthDay.from(myDate);
//        System.out.println(nowDay + " " + myDay);
        System.out.println("今天是你的生日吗？" + myDay.equals(nowDay));
    }

    @Test
    public void test_year_month() {
        YearMonth yearMonth = YearMonth.of(2014, 2);
        System.out.println("YearMonth:" + yearMonth);
        System.out.println(yearMonth + "有多少天？" + yearMonth.lengthOfMonth() + "天");
        System.out.println(yearMonth + "有多少天？" + yearMonth.lengthOfYear() + "天");
        System.out.println(yearMonth + "是闰年？" + (yearMonth.isLeapYear() ? "是" : "否"));
    }

    /*修改日期*/
    @Test
    public void test_modfity_date() {
        LocalDate nowDate = LocalDate.now();
        System.out.println("当前日期：" + nowDate);
        System.out.println("去年的日期：" + nowDate.minusYears(1));
        System.out.println("一个月前的日期：" + nowDate.minusMonths(1));
        System.out.println("一周前:" + nowDate.minusWeeks(1));
        System.out.println("一天前：" + nowDate.minusDays(1));

    }

    /*改变时间*/
    @Test
    public void test_judge_repeat_event() {
        LocalTime nowTime = LocalTime.now();
        System.out.println("当前时间：" + nowTime);
        System.out.println("1小时前：" + nowTime.minusHours(1));
        System.out.println("1分钟前:" + nowTime.minusMinutes(1));
        System.out.println("1秒前：" + nowTime.minusSeconds(1));
        System.out.println("**********************************");
        System.out.println("1小时后：" + nowTime.plusHours(1));
        System.out.println("1分钟后：" + nowTime.plusMinutes(1));
        System.out.println("1秒钟后：" + nowTime.plusSeconds(1));
    }

    /*使用通用方法增减日期\时间*/
    @Test
    public void test_use_commom_minus_plus_unit_to_work() {
        LocalDate nowDate = LocalDate.now();
        System.out.println("当前日期：" + nowDate);
        System.out.println("一年后：" + nowDate.plus(1, ChronoUnit.YEARS));
        System.out.println("一月后：" + nowDate.plus(1, ChronoUnit.MONTHS));
        System.out.println("************************************************************");
        System.out.println("一年前：" + nowDate.minus(1, ChronoUnit.YEARS));
        System.out.println("一月前：" + nowDate.minus(1, ChronoUnit.MONTHS));

        System.out.println("###############################################################");
        LocalTime nowTime = LocalTime.now();
        System.out.println("当前时间：" + nowTime);
        System.out.println("一小时后：" + nowTime.plus(1, ChronoUnit.HOURS));
        System.out.println("一分钟后：" + nowTime.plus(1, ChronoUnit.MINUTES));
        System.out.println("**************************************************************");
        System.out.println("一小时前：" + nowTime.minus(1, ChronoUnit.HOURS));
        System.out.println("一分钟前：" + nowTime.minus(1, ChronoUnit.MINUTES));
    }

    /*时间戳*/
    @Test
    public void test_timestamp() {
        Instant timestamp = Instant.now();
        System.out.println("时间戳：" + timestamp);
        java.util.Date date = Date.from(timestamp);
        System.out.println("时间戳转换为日期：" + date);
        System.out.println("还原时间戳：" + date.toInstant());
    }

    /*格式化日期、时间*/
    @Test
    public void test_format_date_time() {
        LocalDateTime nowDateTime = LocalDateTime.now();
        System.out.println("格式化前的当前日期：" + nowDateTime);
        DateTimeFormatter formatter = DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss");
        String formatDateTime1 = formatter.format(nowDateTime);
        System.out.println("格式化后的当前日期1：" + formatDateTime1);
        String formatDateTime2 = nowDateTime.format(formatter);
        System.out.println("格式化后的当前日期1：" + formatDateTime2);

    }

    /*计算日期差*/
    @Test
    public void test_compute_date_period() {
        LocalDate today = LocalDate.now();
        System.out.println("当前日期：" + today);
        LocalDate birthday = LocalDate.of(1991, 11, 17);
        System.out.println("生日日期：" + birthday);
        /*第二个参数减去第一个参数*/
        Period period = Period.between(birthday, today);
        /*这块得注意下，不是println()方法*/
        System.out.printf("年龄：%d 年 %d 月 %d 日", period.getYears(), period.getMonths(), period.getDays());
    }

    /*提供了使用基于时间的值测量时间量的方法,也可用于 Instant 之间的比较*/
    @Test
    public void test_compute_date_time_duration() {
        LocalDateTime today = LocalDateTime.now();
        System.out.println("当前日期时间：" + today);
        LocalDateTime birthday = LocalDateTime.of(1991, 11, 17, 10, 10, 10);
        Duration between = Duration.between(birthday, today);
        System.out.println("相差的天数 ：" + between.toDays());
        System.out.println("相差的小时数：" + between.toHours());
        System.out.println("相差的分钟数：" + between.toMinutes());
        System.out.println("相差的秒数：" + between.toMillis());
    }

    /*ChronoUnit类可用于在单个时间单位内测量一段时间，这个工具类是最全的了，可以用于比较所有的时间单位*/
    @Test
    public void test_compute_date_time_by_common_api() {
        LocalDateTime today = LocalDateTime.now();
        System.out.println(today);
        LocalDateTime birthday = LocalDateTime.of(1991, 10, 17, 10, 50, 30);
        System.out.println(birthday);
        System.out.println("开始计算...");
        System.out.println("相差的年数：" + ChronoUnit.YEARS.between(birthday, today));
        System.out.println("相差的月数：" + ChronoUnit.MONTHS.between(birthday, today));
        System.out.println("相差的天数：" + ChronoUnit.DAYS.between(birthday, today));
        System.out.println("相差的时数：" + ChronoUnit.HOURS.between(birthday, today));
        System.out.println("相差的分数：" + ChronoUnit.MINUTES.between(birthday, today));

        System.out.println("*************************秒...单位计算如上所示，这种api是一种通用的做法*************************");
    }

}