使用Java的日期差异[重复]

Question

我的发票上有两个日期，

什么是得到这些日期之间的区别的最佳方法？

提前道谢！

Answer 1

假设我的注释中的假设成立，并且您有如下字符串：

String billPeriodStart   = "6 Nov 2019";
String billPeriodEnd     = "3 Feb 2020";
String changePeriodStart = "22 Jan 2020";
String changePeriodEnd   = "3 Feb 2020";

类似这样的方法可能会起作用（未经测试）：

SimpleDateFormat dateFormat = new SimpleDateFormat("dd MMM yyyy");
Date billPeriodStartDate = dateFormat.parse(billPeriodStart);
// same for the other values

Calendar cal = Calendar.getInstance();

cal.setDate(changePeriodStartDate);
cal.add(Calendar.DAY, -1);
Date dateBeforeChangePeriod = cal.getTime();

cal.setDate(changePeriodEndDate);
cal.add(Calendar.DAY, 1);
Date dateAfterChangePeriod = cal.getTime();

boolean hasDaysBeforeChangePeriod = !dateBeforeChangePeriod.before(billPeriodStartDate);
boolean hasDaysAfterChangePeriod  = !dateAfterChangePeriod.after(billPeriodEndDate);

if (hasDaysBeforeChangePeriod) {
  // print billPeriodStartDate to dateBeforeChangePeriod 
}
if (hasDaysAfterChangePeriod) {
  // print dateAfterChangePeriod to billPeriodEndDate
}
if (!hasDaysBeforeChangePeriod && !hasDaysAfterChangePeriod) {
  // print "none"
}