本人在工作開發中遇到了這樣一個需求，已知年份和月份獲取該月所包含的所有周列表，於是實現了一個不算完整的演算法計算出了該月所包含的周列表，程式碼寫的可能比較複雜，煩請各位觀客幫忙優化。

public static void main(String[] args) {
        List<Integer[]> list= getWeeks(2015, 4);
        for (Integer[] integers : list) {
                         System.out.println(integers[0]+"~"+integers[6
 
]+"日");
        }
    }
    /**
     * 給定年份和月份獲取當月周列表
     * @params year
     * @params month
     * */
    private static List<Integer[]> getWeeks(int year, int month) {
        List<Integer[]> weeks = new ArrayList<Integer[]>();
        // 獲取上個月的最後一天日期 和本月的最後一天日期
        // 取得系統當前時間
        Calendar cal = Calendar.getInstance();
        cal.set
 
(Calendar.YEAR, year);
        cal.set(Calendar.MONTH, month);
        int currentMonthDayCount = cal.getActualMaximum(Calendar.DAY_OF_MONTH);
        // 取得系統當前時間所在月第一天時間物件
        cal.set(Calendar.DAY_OF_MONTH, 1);
        // 日期減一,取得上月最後一天時間物件
        cal.add(Calendar.DAY_OF_MONTH, -1);
        int lastMonthDayCount = cal.get
 
(Calendar.DAY_OF_MONTH);
        cal.set(Calendar.YEAR, year);
        cal.set(Calendar.MONTH, month);
        cal.set(Calendar.DATE, 1);
        while (cal.get(Calendar.DAY_OF_WEEK) != Calendar.SUNDAY) {
            cal.add(Calendar.DATE, 1);
        }
        int currentMonthFirstSunday = cal.get(Calendar.DAY_OF_MONTH);
        System.out.println(currentMonthDayCount+"  "+currentMonthFirstSunday+"  "+lastMonthDayCount);
        int sunday = currentMonthFirstSunday-7;
        while (sunday<currentMonthDayCount) {
            Integer[] weekArr = new Integer[7];
            for (int i = 0; i < weekArr.length; i++) {
                sunday = sunday+1;
                weekArr[i] = sunday;

            }
            weeks.add(weekArr);
        }
        Integer[] firstWeek = weeks.get(0);
        int firstDayOfWeek = firstWeek[0]+lastMonthDayCount;
        if (firstDayOfWeek<=lastMonthDayCount) {
            int index = 0;
            for (int i = firstDayOfWeek; i <= lastMonthDayCount; i++) {
                weeks.get(0)[index] = i;
                index++;
            }
        }
        Integer[] lastWeek = weeks.get(weeks.size()-1);
        int lastDayOfWeek = lastWeek[6];
        if (lastDayOfWeek>currentMonthDayCount) {
            int outOfMonthCount = lastDayOfWeek-currentMonthDayCount;
            int index = 1;
            for (int i = outOfMonthCount; i >=1 ; i--) {
                weeks.get(weeks.size()-1)[7-index] = i;
                index++;
            }
        }
        return weeks;
    }

以上就是本人程式碼 控制檯輸出如下
31 3 30
27~3日
4~10日
11~17日
18~24日
25~31日