date4j是一个用于简化日期和时间操作的Java工具。可以替换java.util.Date。



示例代码：



DateTime dateAndTime = new DateTime("2010-01-19 23:59:59") DateTime dateAndTime = new DateTime("2010-01-19 23:59:59.123456789") DateTime dateOnly = new DateTime("2010-01-19") DateTime timeOnly = new DateTime("23:59:59") DateTime dateOnly = DateTime.forDateOnly(2010,01,19) DateTime timeOnly = DateTime.forTimeOnly(23,59,59,0) DateTime dt = new DateTime("2010-01-15 13:59:15") boolean leap = dt.isLeapYear() //falsedt.getNumDaysInMonth() //31dt.getStartOfMonth() //2010-01-01, 00:00:00.000000000dt.getEndOfDay() //2010-01-15, 23:59:59.999999999dt.format("YYYY-MM-DD") //formats as 2010-01-15 dt.plusDays(30) //30 days after Jan 15dt.numDaysFrom(someDate) //returns an intdueDate.lt(someDate) //less-thandueDate.lteq(someDate) //less-than-or-equal-to- date4j, an alternative to Date, Calendar, and related Java classes. The JDK s treatment of dates is likely the single most suctorial aspect of the Java core libraries. It needs improvement.



The main goals of date4j are :



■easy manipulation of dates/times in the Gregorian calendar (the civil calendar used in almost all countries).

■easy storage and retrieval of such dates/times from a relational database.

■a simplified model of civil timekeeping, similar to the model used by many databases.