Java 使用stream()兩個集合根據元素中的某個字段取交集

list1<Bean1>和list2<Bean2> 根據元素的playerId屬性 取交集

Bean1和Bean2 都含有playerId屬性

List<Bean1> intersectList = list1.stream()
                        .filter(pe -> find1(pe.getPlayerId(), list2) > -1).collect(Collectors.toList());

輔助方法find1

public int find1(long playerId,List<PlayerExtra> list) {
        int res = -1;
        for (int i = 0; i < list.size(); i++) {
            if (list.get(i).getPlayerId() == playerId) {
                res = i;
                break;
            }
        }
        return res;
    }