如何通过检查数组值将数组拆分为不同的数组或同一数组的不同键

Question

calendarday: [CalendarDay{2017-8-13}, CalendarDay{2017-8-14}, CalendarDay{2017-9-18}, CalendarDay{2017-9-19}, CalendarDay{2017-10-15}, CalendarDay{2017-10-16}]

calendarday: [CalendarDay{2017-8-13}, CalendarDay{2017-8-14}]

calendardayone: [CalendarDay{2017-9-18}, CalendarDay{2017-9-19}]

calendarday: [
0:[CalendarDay{2017-8-13}, CalendarDay{2017-8-14}],
1:[CalendarDay{2017-9-18}, CalendarDay{2017-9-19}], 
2:[CalendarDay{2017-10-15}, CalendarDay{2017-10-16}]
]

Answer 1

这就是我正在考虑的解决方案：将所有calendarday保存在字典中，关键字是月份。所以我们从这样的事情开始：

String[] array = {"CalendarDay{2017-8-13}", "CalendarDay{2017-8-14}", "CalendarDay{2017-9-18}", "CalendarDay{2017-9-19}", "CalendarDay{2017-10-15}", "CalendarDay{2017-10-16}"};

然后简单地迭代数组，拆分每个字符串并保存到字典中：

Map<String, ArrayList<String>> dictionary = new HashMap<String, ArrayList<String>>();
for (String currentString : array) {
    String month = currentString.split("-")[1];
    ArrayList<String> values = dictionary.get(month);
    if (values == null) {
        values = new ArrayList<String>();
    }
    values.add(currentString);
    dictionary.put(month, values);
}

我们最终会得到这样的结果：

{
    8=[CalendarDay{2017-8-13}, CalendarDay{2017-8-14}], 
    9=[CalendarDay{2017-9-18}, CalendarDay{2017-9-19}], 
    10=[CalendarDay{2017-10-15}, CalendarDay{2017-10-16}]
}