ChronoUnit
一组标准的日期时间单位。这组单元提供基于单元的访问来操纵日期，时间或日期时间。 可以通过实现TemporalUnit来扩展标准单元集。
这些单元适用于多个日历系统。
例如，大多数非ISO日历系统定义年，月和日的单位，只是略有不同的规则。 每个单元的文档说明了它的运作方式。
这是一个最终的、不可变的和线程安全的枚举。
入门例子
plus() 测试
@Test
public void testChromoUnitsPlus() {
//Get the current date
LocalDate today = LocalDate.now();
System.out.println("Current date: " + today);
//add 1 week to the current date
LocalDate nextWeek = today.plus(1, ChronoUnit.WEEKS);
System.out.println("Next week: " + nextWeek);
//add 1 month to the current date
LocalDate nextMonth = today.plus(1, ChronoUnit.MONTHS);
System.out.println("Next month: " + nextMonth);
//add 1 year to the current date
LocalDate nextYear = today.plus(1, ChronoUnit.YEARS);
System.out.println("Next year: " + nextYear);
//add 10 years to the current date
LocalDate nextDecade = today.plus(1, ChronoUnit.DECADES);
System.out.println("Date after ten year: " + nextDecade);
}
日志信息
Current date: 2019-02-27
Next week: 2019-03-06
Next month: 2019-03-27
Next year: 2020-02-27
Date after ten year: 2029-02-27between
@Test
public void testChromoUnitsBetween() {
//Get the current date
LocalDate today = LocalDate.now();
LocalDate nextWeek = today.plus(1, ChronoUnit.WEEKS);
long diff = ChronoUnit.WEEKS.between(today, nextWeek);
Assert.assertEquals(1, diff);
}
