java 从 List<Date> 创建一个 List<List<Date>> ，其中包含随后放入 Lists 的所有日期
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Create from a List<Date> a List<List<Date>> that has all Dates which are subsequently put in Lists
提问by tzippy
I hope you understood me. Hard to describe in english for me. So I have a List of sorted Date Objects. Now I want to put all Dates that are in a row (12/16/09, 12/17/09, 12/18/09...) in a List of their own. Stand-alone-Dates shall also be put in a List of their own.
我希望你理解我。对我来说很难用英语描述。所以我有一个排序的日期对象列表。现在我想将所有连续的日期（12/16/09、12/17/09、12/18/09...）放在他们自己的列表中。独立日期也应放在它们自己的列表中。
So from (12/01/09; 12/02/09; 12/03/09; 12/06/09; 12/10/09; 12/17/09; 12/18/09; 12/31/09)I want to create
所以从(12/01/09; 12/02/09; 12/03/09; 12/06/09; 12/10/09; 12/17/09; 12/18/09; 12/31/09)我想创造
[(12/01/09; 12/02/09; 12/03/09)(12/06/09)(12/10/09)(12/17/09; 12/18/09)(12/31/09)]
The code I have works. But it is so complicated I was wondering if maybe there is an easier way. Unfortunately I can't use Joda-Time. maybe someone has done it before...
我的代码有效。但它是如此复杂，我想知道是否有更简单的方法。不幸的是，我不能使用 Joda-Time。也许之前有人做过...
public List<List<Date>> listOfDatestoList(List<Date> dates){
List<List<Date>> list = new ArrayList<List<Date>>();
List<Date> theseDates = new ArrayList<Date>();
if(dates.size() == 1){
theseDates.add(dates.get(0));
list.add(theseDates);
return list;
}
for (int i = 0; i < dates.size() - 1; i++) {
Calendar cal1 = Calendar.getInstance();
Calendar cal2 = Calendar.getInstance();
//Die ersten beiden Daten der Liste werden verglichen
cal1.setTime(dates.get(i));
cal2.setTime(dates.get(i + 1));
cal1.add(Calendar.DAY_OF_YEAR, 1);
if(cal1.equals(cal2)){
theseDates.add(dates.get(i));
}
else if(theseDates.size() > 0){
theseDates.add(dates.get(i));
List<Date> tempList = new ArrayList<Date>();
for(Date date : theseDates){
tempList.add(date);
}
list.add(tempList);
theseDates = new ArrayList<Date>();
}
else{
List<Date> tempList = new ArrayList<Date>();
tempList.add(dates.get(i));
list.add(tempList);
}
if(i == dates.size() - 2){
if(cal1.equals(cal2)){
theseDates.add(dates.get(i + 1));
}
if(theseDates.size() > 0 ){
list.add(theseDates);
theseDates = new ArrayList<Date>();
}
else{
List<Date> tempList = new ArrayList<Date>();
tempList.add(dates.get(i+1));
list.add(tempList);
}
}
}
return list;
}
回答by Mike Q
An attempt, not tested but should be close to what you need (some date code pseudo-coded)
尝试，未测试但应该接近您的需要（一些日期代码伪编码）
List<Date> dates = ...;
List<List<Date>> dateList = new ArrayList<List<Date>>();
List<Date> currentList = new ArrayList<Date>();
for (Date date : dates)
{
if (currentList.isEmpty())
{
currentList.add(date);
continue;
}
Date lastDate = currentList.get(currentList.size() - 1);
if (date is one day after lastDate)
{
currentList.add(date);
continue;
}
dateList.add(currentList);
currentList = new ArrayList<Date>();
currentList.add(date);
}
if (!currentList.isEmpty())
dateList.add(currentList);
