//獲得本月第一天0點時間
public static long getTimesMonthmorning(int a){
        Calendar c = Calendar.getInstance();
        c.add(Calendar.MONTH, -a);
        c.set(Calendar.DAY_OF_MONTH, 1);//設定為1號,當前日期既為本月第一天
//將小時至0
c.set(Calendar.HOUR_OF_DAY, 0);
//將分鐘至0
c.set(Calendar.MINUTE, 0);
//將秒至0
c.set(Calendar.SECOND,0);
//將毫秒至0
 
c.set(Calendar.MILLISECOND, 0);
// 獲取本月第一天的時間戳
return c.getTimeInMillis();
    }
    //獲得本月最後一天0點時間
public static long getTimesMonthLastTime(int a){
//獲取當前月最後一天
Calendar ca = Calendar.getInstance();
        ca.add(Calendar.MONTH, -a);
        ca.set(Calendar.DAY_OF_MONTH, ca.getActualMaximum(Calendar.DAY_OF_MONTH
 
));
//將小時至0
ca.set(Calendar.HOUR_OF_DAY, 0);
//將分鐘至0
ca.set(Calendar.MINUTE, 0);
//將秒至0
ca.set(Calendar.SECOND,0);
//將毫秒至0
ca.set(Calendar.MILLISECOND, 0);
// 獲取本月最後一天的時間戳
return (ca.getTimeInMillis()+86400000);
    }

    public static void main(String [] args){
        System.out.print(getTimesMonthmorning(2)+"\n"+getTimesMonthLastTime
 
(2)+"'''111");
    }