java中扩展DateTime简介说明

DateTime简介

DateTime是我们日常开发中
    经常需使用的对象
那么有没有一种非常易用的DateTime呢?
下文笔者将一一道来,如下所示

//引入org.joda.time.DateTime
<dependency>
   <groupId>joda-time</groupId>
   <artifactId>joda-time</artifactId>
   <version>2.9.8</version>
</dependency>

//1.初始化时间
DateTime time = new DateTime(2023,5,17,18,6,12,666);
// 2023年5月17日18点6分12秒666毫秒

//2.按格式输出时间(将DateTime格式转换为字符串)
 String time = dateTime.toString("yyyy-MM-dd hh:mm:ss.SSSa");
 小写hh是12小时制,大写HH是24小时制

//3.将字符串转换为DateTime格式
 DateTimeFormatter format = DateTimeFormat .forPattern("yyyy-MM-dd HH:mm:ss");  
  //DateTime dateTime = DateTime.parse("2023-5-17 14:20:11", format); 

//4.取得当前时间
DateTime time= new DateTime();

//5.计算两个日期间隔的天数
 LocalDate start=new LocalDate(2023,5,17);    
 LocalDate end=new LocalDate(2022, 06, 12);    
 int days = Days.daysBetween(start, end).getDays(); 

//6.增加日期
      DateTime dateTime = DateTime.parse("2023-05-17");  
                dateTime = dateTime1.plusDays(1);  
                dateTime = dateTime1.plusHours(2);  
                dateTime = dateTime1.plusMinutes(3);  
                dateTime = dateTime1.plusMonths(4);  
                dateTime = dateTime1.plusSeconds(5);  
                dateTime = dateTime1.plusWeeks(6);  
                dateTime = dateTime1.plusYears(7);  

//7.减少日期
  DateTime dateTime = DateTime.parse("2023-05-17");  
                dateTime = dateTime1.minusMillis(1);  
                dateTime = dateTime1.minusHours(1);  
                dateTime = dateTime1.minusSeconds(1);;  

//8.判断是否闰月
DateTime time = new DateTime();    
 org.joda.time.DateTime.Property month = time.monthOfYear();    
  System.out.println("是否闰月:" + month.isLeap());  

//9.DateTime与Date转换
DateTime time = new DateTime(new Date());    
 Date date = time.toDate();    
 DateTime time2 = new DateTime(System.currentTimeMillis());    
 time2.getMillis();  

//10.DateTime与Calendar转换
Calendar calendar = Calendar.getInstance();    
 dateTime = new DateTime(calendar);