import java.time.*;

import java.time.format.DateTimeFormatter;

public class App

{

    public static void main( String[] args )

    {

        LocalDateTime time = LocalDateTime.now();

        System.out.println(time.toString()); //输出日期时间：2019-05-04T18:27:55.240

        System.out.println(time.toLocalDate());  //输出日期：2019-05-04

        System.out.println(time.toLocalTime());  //输出时间：18:27:55.240

        System.out.println(time.getDayOfMonth()); //输出当前日期月份的第几天：4

        System.out.println(time.getDayOfWeek()); //输出档期日期周几：SATURDAY

        System.out.println(time.getDayOfYear()); //当前日期在该年属于第几天：124

        System.out.println(time.getHour());  //输出：18

        System.out.println(time.getMinute()); //输出：27

        System.out.println(time.getSecond()); //输出：55

        System.out.println(time.getMonthValue()); //输出：5

        System.out.println(time.getMonth());  //输出：MAY

        System.out.println("==============================================");

        //格式化输出：

        DateTimeFormatter format = DateTimeFormatter.ofPattern("YYYY-MM-dd HH:mm:ss");

        System.out.println(time.format(format));  //输出：2019-05-04 18:27:55

        //构造时间

        LocalDateTime startTime = LocalDateTime.of(2019,05,04,17,59);

        System.out.println(startTime.format(format));  //输出：2019-05-04 17:59:00

        LocalDateTime endTime = LocalDateTime.of(LocalDate.now(), LocalTime.of(0,0,0));

        System.out.println(endTime.format(format));  //输出：2019-05-04 00:00:00

        //时间比较

        System.out.println(time.isAfter(startTime));  //输出：true

        System.out.println(time.isBefore(endTime));  //输出：false

        //时间运算

        System.out.println(time.plusDays(-1).format(format)); //输出：2019-05-03 18:27:55

        System.out.println(time.plusDays(1).format(format));  //输出：2019-05-05 18:27:55

        System.out.println(time.plusMonths(-1).format(format));  //输出：2019-04-04 18:27:55

        System.out.println(time.plusMonths(1).format(format));  //输出：2019-06-04 18:27:55

        System.out.println(time.getHour());  //输出：18

        System.out.println(time.withHour(1).format(format));  //输出：2019-05-04 01:27:55

        //获取毫秒数时间戳

        long milliSec = time.atZone(ZoneId.systemDefault()).toInstant().toEpochMilli();

        System.out.println(milliSec);  //输出：1556965675240

        //获取秒数时间戳

        long sec = time.atZone(ZoneId.systemDefault()).toInstant().getEpochSecond();

        System.out.println(sec);  //输出：1556965675

        //时间戳转换为时间

        LocalDateTime time2 =LocalDateTime.ofInstant(Instant.ofEpochMilli(milliSec),ZoneId.systemDefault());

        System.out.println(time2.format(format));  //输出：2019-05-04 18:27:55

        LocalDateTime time3 = LocalDateTime.ofInstant(Instant.ofEpochSecond(sec),ZoneId.systemDefault());

        System.out.println(time3.format(format));  //输出：2019-05-04 18:27:55

    }

}

2019-05-04T18:27:55.240

2019-05-04

18:27:55.240

4

SATURDAY

124

18

27

55

5

MAY

==============================================

2019-05-04 18:27:55

2019-05-04 17:59:00

2019-05-04 00:00:00

true

false

2019-05-03 18:27:55

2019-05-05 18:27:55

2019-04-04 18:27:55

2019-06-04 18:27:55

18

2019-05-04 01:27:55

1556965675240

1556965675

2019-05-04 18:27:55

2019-05-04 18:27:55