在 ArrayList 中查找并添加多个值

Question

我想从给定的示例数据中添加 programPercentTotalViewed，其中 programId 与 ArrayList 相同，例如 programId= 59554。 我该怎么做。

1- programId=59554, programPercentTotalViewed=50 
2- programId=30583, programPercentTotalViewed=15 
3- programId=59554, programPercentTotalViewed=5 
4- programId=30583, programPercentTotalViewed=5 
5- programId=59554, programPercentTotalViewed=5 
6- programId=30583, programPercentTotalViewed=5 
7- programId=59554, programPercentTotalViewed=5

    List<LiveEventsDto> eventsList = liveEvents;
        Set<String> names = new HashSet<String>();
        for (LiveEventsDto singleEvent : eventsList) {
            if (names.contains(singleEvent.getProgramId())) {
                System.out.println("Because same programId exists: " + singleEvent.getProgramId());
                System.out.println("ProgramPercentTotalViewed: " + singleEvent.getProgramPercentTotalViewed());

            } else {
                System.out.println("Because same programId  DOES NOT exists: " + singleEvent.getProgramId());
            }
        }

Answer 1

通常是这样的：

Map<Integer, Integer> sums = new HashMap<>();
for (LiveEventsDto car: cars) {
    int key = car.getProgramId();
    int count = car.getProgramPercentTotalViewed();
    if (sums.containsKey(key) {
        count += sums.get(key);
    }
    sums.put(key, count);
}