Java：joda-time处理时间对象

<dependency>
     <groupId>joda-time</groupId>
     <artifactId>joda-time</artifactId>
     <version>2.10.5</version>
 </dependency>

package org.example;

import org.joda.time.DateTime;
import org.joda.time.Days;
import org.joda.time.format.DateTimeFormat;
import org.joda.time.format.DateTimeFormatter;

import java.util.Date;

public class JodaTimeTest {
public static void main(String[] args) {
/**
* 获取 DateTime
*/
// 构造函数 现在时间
DateTime dt1 = new DateTime();
System.out.println(dt1);
// 2020-06-21T10:54:11.378+08:00

// 静态方法 现在时间
DateTime dt2 = DateTime.now();
System.out.println(dt2);
// 2020-06-21T10:54:11.444+08:00

// long -> DateTime
DateTime dt3 = new DateTime(1609294356000L);
System.out.println(dt3);
// 2020-12-30T10:12:36.000+08:00

// int -> DateTime
DateTime dt4 = new DateTime(2020, 1, 12, 12, 30, 53);
System.out.println(dt4);
// 2020-01-12T12:30:53.000+08:00

// Date -> DateTime
DateTime dt5 = new DateTime(new Date());
System.out.println(dt5);
// 2020-06-21T10:47:01.461+08:00

// 解析时间 String -> DateTime
DateTimeFormatter formatter = DateTimeFormat.forPattern("yyyy-MM-dd HH:mm:ss");
DateTime dt6 = DateTime.parse("2020-12-30 10:12:36", formatter);
System.out.println(dt6);
// 2020-12-30T10:12:36.000+08:00

/**
* DateTime 转为其他对象
*/
// 格式化时间 DateTime -> String
System.out.println(dt6.toString("yyyy-MM-dd HH:mm:ss"));
// 2020-12-30 10:12:36

// 获取13位时间戳 DateTime -> Long
System.out.println(dt6.getMillis());
// 1609294356000

// DateTime -> int
System.out.println(dt6.getYear());
System.out.println(dt6.getMonthOfYear());
System.out.println(dt6.getDayOfMonth());
System.out.println(dt6.getHourOfDay());
System.out.println(dt6.getMinuteOfHour());
System.out.println(dt6.getSecondOfMinute());
System.out.println(dt6.getMillisOfSecond());
// 2020 12 30 10 12 36 0

// DateTime -> Date
System.out.println(dt6.toDate());
// Wed Dec 30 10:12:36 CST 2020

/**
* 时间修改 with开头
*/
DateTime dt7 = dt6.withYear(1)
.withMonthOfYear(2)
.withDayOfMonth(3)
.withHourOfDay(4)
.withMinuteOfHour(5)
.withSecondOfMinute(6)
.withMillisOfSecond(7);

System.out.println(dt7);
// 0001-02-03T04:05:06.007+08:05:43

/**
* 时间计算 plus(+) 或者 minus(-)开头
*/

DateTime dt8 = dt7.plusYears(7)
.plusMonths(6)
.plusDays(5)
.plusHours(4)
.plusMinutes(3)
.plusSeconds(2
.plusMillis(1);

System.out.println(dt8);
// 0008-08-08T08:08:08.008+08:05:43

/**
* 计算两个时间间隔天数
*/

DateTime dt9 = new DateTime(2020, 10, 20, 10, 30, 12);
DateTime dt10 = new DateTime(2020, 10, 30, 20, 30, 12);
System.out.println(Days.daysBetween(dt9, dt10).getDays());
// 10
}
}