嵌套for循环和数组索引越界异常时出现问题

Question

我正在为一个老式电话计划编写Java代码，所以我有：

• 频段类:公共频段（LocalTime startTime,LocalTime endTime,DayofWeek[]combinedDays,double intervalCost）
• 速率类:Public Rate（String name，BAND[]BAND，int intervalMs，double startCost,String numberRoot)

我想在Rate类中编写一个私有Band[]selectBandsInDay(DayOfWeekDay)方法，如果给定一周中的某一天，它将返回一个由该周中某一天的带组成的带数组。

我写的是：

private Band[] selectBandsInDay(DayOfWeek day) {
        
        Band[] bandsInDay = new Band[bands.length];
        int size = 0;
        
        for (int i=0; i<bands.length; i++) {
            for (int j=0; j<bands.length; j++) {
                if (bands[j].getCombinedDays()[i] == day) {
                bandsInDay[size] = bands[i];
                size++;
                }
            }
        }       
        return bandsInDay;
    }

但是我一直得到一个索引越界异常（索引2越界，长度为2）。

我怎么能解决这个？

Answer 1

我不得不用另一种方法。

private Band[] selectBandsInDay(DayOfWeek day) {
        
        int i = 0;
        int length = 0;
        for (Band band : bands) {
            if(DayOfWeekHelper.isDayIn(day, band.getCombinedDays()))
                length++;
        }
        Band[] bands_1 = new Band[length];
        for (Band band : bands) {
            if(DayOfWeekHelper.isDayIn(day, band.getCombinedDays()))
                bands_1[i++] = band;
        }
        return bands_1;
    }

我使用isDayIn（）方法创建了DayOfWeekHelper类：

public class DayOfWeekHelper {
    public static boolean isDayIn(DayOfWeek day, DayOfWeek[] combinedDays) {
        for (DayOfWeek d : combinedDays) {
            if (d == day)  {
                return true;
            }
        }
        return false;
    }
}