java.lang.IllegalStateException: Duplicate key 0

https://blog.csdn.net/qq_40366738/article/details/114754348

集合转map，重复key的问题

public class Test {
    public static void main(String[] args) {
        List<Map.Entry> list = new ArrayList<>();
        for (int i = 0; i < 3; i++) {
            Map.Entry entry = new AbstractMap.SimpleEntry<>(1,i);
            list.add(entry);
        }
        Map<Object, Object> map = list.stream().collect(
                Collectors.toMap(
                        Map.Entry::getKey,
                        Map.Entry::getValue,
                        //以最后一个元素为准，更新
                        //(e1,e2) -> e2
                        //以第一个元素为准，不更新
                        (e1,e2) -> e1
                ));
        System.out.println(map);
    }
}