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我在建立自己的課程時有些困難，我知道有些課程已經開課了，但由於內部限制，我必須實施自己的課程。 構造函數（下面的代碼）基本上接受2個日期，一個開始和一個結束，方法makeWeeks（），將這個時期劃分爲幾個星期，我根據我學習時學習的「頭尾」名單。創造我自己的期間課程時的艱難時期
繼承人的代碼（要點）
public class Period implements Serializable
{
private static final long serialVersionUID = 1L;
private Calendar start;
private Calendar end;
private long durationMillis;
private long startMillis;
private long endMillis;
private long MAX = 604800000; //A week in millis
private long DAY = 86400000;
private long SIX = 518400000;
private ArrayList<Week> weeks;
public Period(Calendar start, Calendar end)
{
this.start = start;
this.end = end;
startMillis = start.getTimeInMillis();
endMillis = end.getTimeInMillis();
durationMillis = endMillis - startMillis;
int startWeek = start.get(Calendar.WEEK_OF_YEAR);
int endWeek = end.get(Calendar.WEEK_OF_YEAR);
weeks = new ArrayList<Week>();
}
/**
* Construct the weeks in this period
*
* @return
*/
public ArrayList<Week> makeWeeks()
{
long borderLine;
if ((durationMillis < MAX) || (endMillis < startMillis))
{
return null;
}
Calendar endHead = Calendar.getInstance();
//If first week is not Monday then count the days that have been completed
if (start.get(Calendar.DAY_OF_WEEK) != Calendar.MONDAY)
{
int days = 0;
start = adjustCalendar(start);//Set time to 0:0:0:0
days = getDaysToMonday(start.get(Calendar.DAY_OF_WEEK));
endHead.setTimeInMillis(start.getTimeInMillis());
endHead.add(Calendar.DAY_OF_YEAR, days - 1);
weeks.add(new Week(start, endHead, days, calcCompletion(days), setWeekNumber(start)));//was endHead
borderLine = endHead.getTimeInMillis() + DAY;
}//head week set
else
{
start = adjustCalendar(start);
endHead.setTimeInMillis(start.getTimeInMillis());//Successful
borderLine = endHead.getTimeInMillis();
}
long endMillis = 0;
while ((((borderLine + SIX)) < (end.getTimeInMillis() + 1)))
{
Calendar endNext = Calendar.getInstance();
Calendar begin = Calendar.getInstance();
begin.setTimeInMillis(borderLine);
endNext.setTimeInMillis(borderLine + SIX);
weeks.add(new Week(begin, endNext, 7, true, setWeekNumber(begin)));
borderLine += MAX;
endMillis = endNext.getTimeInMillis();
}
//adjust Tail
Calendar tail = Calendar.getInstance();
tail.setTimeInMillis(endMillis + DAY);//the beginning of the tail
tail = adjustCalendar(tail);//set to 00:00:00
int daysTail = getDaysToTail(end.get(Calendar.DAY_OF_WEEK) + 1);
if (daysTail != 0)
{
weeks.add(new Week(tail, end, daysTail, calcCompletion(daysTail), setWeekNumber(end)));
}
return weeks;
}//EOF makeweeks
private int setWeekNumber(Calendar cal)
{
return cal.get(Calendar.WEEK_OF_YEAR);
}
/**
* This method returns the amount of days between the given day and the next coming Monday
*/
private int getDaysToMonday(int currentDay)
{
switch (currentDay)
{
case 1://sunday
return 1;
case 2://monday
return 0;
case 3://tuesday
return 6;
case 4://wednesday
return 5;
case 5://thursday
return 4;
case 6://friday
return 3;
case 7://saturday
return 2;
}
return 0;
}//EOF method
/**
* Returns the day to the end of the final week, always start counting from a Monday
*
* @return
*/
private int getDaysToTail(int tailDay)
{
switch (tailDay)
{
case 1://sunday
return 0;
case 2://monday
return 1;
case 3://tuesday
return 2;
case 4://wednesday
return 3;
case 5://thursday
return 4;
case 6://friday
return 5;
case 7://saturday
return 6;
}
return 0;
}
/**
* Returns the amount of weeks stored in this period, completed and non
*
* @return
*/
public int totalWeeks()
{
return weeks.size();
}
/**
* Tells us if the selected period is at least one week
* will return no result.
*
* @return
*/
public boolean isAtleastWeek()
{
long diff = end.getTimeInMillis() - start.getTimeInMillis();
if (diff < MAX)
{
return false;
}
return true;
}
/**
* Provided a week-number, gives back a Week marked by that week-number, if existing.
*
* @param weekNumber
* @return
*/
public Week getWeek(Double weekNumber)
{
int weekNumberInt = weekNumber.intValue();
for (Week week : weeks)
{
if (weekNumberInt == week.getWeekNumber())
{
return week;
}
}
return null;
}
/**
* This method will set the calendars time (H:M:S:M) to 0:0:0:0 so to be able to calculate a precise start and End,
* dates will remain unaltered
*
* @param cal
* @return
*/
private Calendar adjustCalendar(Calendar nu)
{
nu.set(Calendar.HOUR, 0);
nu.set(Calendar.MINUTE, 0);
nu.set(Calendar.SECOND, 0);
nu.set(Calendar.MILLISECOND, 0);
return nu;
}
我怕有什麼不對，這工作正常在大多數情況下，但在某些情況下，（如月和2011年12月），第二週是不是收集，並在2012年3月，如果您設置爲2012年3月31日結束，則不收集最後一週，但如果您選擇2012年3月30日結束。 你有什麼建議嗎？
什麼「內部限制」阻止您使用其他庫？日曆邏輯是一些最複雜，非常平凡的代碼，可能在_existence_中，正如http://stackoverflow.com/questions/6841333/why-is-subtracting-these-two-times-in-1927-giving-一個奇怪的結果。 –
我需要實現我自己的，因爲這將作爲其他擴展的核心類，此外，這需要適應需要特定代碼實現的特定體系結構，我不能使用其他時間容器 – JBoy
......即便如此，我認爲「無bug日曆邏輯」是至少需要十幾個Jon Skeet口徑專家進行幾個月工作的任務;我會盡全力避免它。 –