我正在开发一个应用程序，我在每次使用之间存储一些信息，这些数据基本上可以归结为计算今天、本周、本月和应用程序生命周期中发生的事件的次数。我将此数据存储在 4 个不同的计数器中，我可以使用 SharedPreferences 加载/保存。
除了我将应用程序的“上次运行时间”存储为日期的数据之外，我的计划是在加载期间我将加载计数器，然后根据今天的日期测试存储的日期以确定需要清除哪些计数器。
听起来很简单吧！
在把我的头发拉出来一段时间并通过日历文档来回前进之后，我认为我对它们的理解足以提出以下内容：
Calendar last = Calendar.getInstance();
last.setTimeInMillis(lastDate);
Calendar today = Calendar.getInstance();
today.add(Calendar.DATE, -1);
if ( !last.after(today) )
{
today = 0;
}
today.add(Calendar.WEEK_OF_MONTH, -1);
today.set(Calendar.DAY_OF_WEEK, Calendar.SUNDAY);
if ( !last.after(today) )
{
today = 0;
week = 0;
}
today = Calendar.getInstance();
today.add(Calendar.MONTH, -1);
today.set(Calendar.DATE, today.getActualMaximum(Calendar.DATE));
if ( !last.after(today) )
{
today = 0;
week = 0;
month = 0;
}
我认为这应该没问题，但是我遇到的问题是测试，今天的测试很容易，但是测试月份逻辑需要等待一个月，或者编写一个使用日历 API 模拟旧日期的测试用例，但是我如果我对 API 工作原理的假设首先是错误的，则无法编写测试用例！
因此，在一大段文字之后，我的问题是......上面的代码块看起来很正常，还是我完全误解了在 Java 中使用日期？
谢谢！
编辑：
第二遍代码：
这看起来更明智吗？如果我理解正确，我现在正尝试将上次保存的日期的结束时间与今天、本周和本月的开始时间进行比较。
Calendar last = Calendar.getInstance();
last.setTimeInMillis(lastDate);
last.set(Calendar.HOUR_OF_DAY, last.getActualMaximum(Calendar.HOUR_OF_DAY));
last.set(Calendar.MINUTE, last.getActualMaximum(Calendar.MINUTE));
last.set(Calendar.SECOND, last.getActualMaximum(Calendar.SECOND));
last.set(Calendar.MILLISECOND, last.getActualMaximum(Calendar.MILLISECOND));
Calendar todayStart = Calendar.getInstance();
todayStart.set(Calendar.HOUR_OF_DAY, todayStart.getActualMinimum(Calendar.HOUR_OF_DAY));
todayStart.set(Calendar.MINUTE, todayStart.getActualMinimum(Calendar.MINUTE));
todayStart.set(Calendar.SECOND, todayStart.getActualMinimum(Calendar.SECOND));
todayStart.set(Calendar.MILLISECOND, todayStart.getActualMinimum(Calendar.MILLISECOND));
// If the last recorded date was before the absolute minimum of today
if ( last.before(todayStart) )
{
todayCount = 0;
}
Calendar thisWeekStart = Calendar.getInstance();
thisWeekStart.set(Calendar.HOUR_OF_DAY, thisWeekStart.getActualMinimum(Calendar.HOUR_OF_DAY));
thisWeekStart.set(Calendar.MINUTE, thisWeekStart.getActualMinimum(Calendar.MINUTE));
thisWeekStart.set(Calendar.SECOND, thisWeekStart.getActualMinimum(Calendar.SECOND));
thisWeekStart.set(Calendar.DAY_OF_WEEK, thisWeekStart.getFirstDayOfWeek());
thisWeekStart.set(Calendar.MILLISECOND, thisWeekStart.getActualMinimum(Calendar.MILLISECOND));
// If the last date was before the absolute minimum of this week then clear
// this week (and today, just to be on the safe side)
if ( last.before(thisWeekStart) )
{
todayCount = 0;
weekCount = 0;
}
Calendar thisMonthStart = Calendar.getInstance();
thisMonthStart.set(Calendar.HOUR_OF_DAY, thisMonthStart.getActualMinimum(Calendar.HOUR_OF_DAY));
thisMonthStart.set(Calendar.MINUTE, thisMonthStart.getActualMinimum(Calendar.MINUTE));
thisMonthStart.set(Calendar.SECOND, thisMonthStart.getActualMinimum(Calendar.SECOND));
thisMonthStart.set(Calendar.DAY_OF_MONTH, thisMonthStart.getActualMinimum(Calendar.MONTH));
thisMonthStart.set(Calendar.MILLISECOND, thisMonthStart.getActualMinimum(Calendar.MILLISECOND));
// If the last date was before the absolute minimum of this month then clear month...
if ( !last.after(thisMonthStart) )
{
todayCount = 0;
weekCount = 0;
monthCount = 0;
}