本文共 1494 字，大约阅读时间需要 4 分钟。

List
   
     listIds = Arrays.asList(str.split(",")).stream().map(s -> Long.parseLong(s.trim())).collect(Collectors.toList());
   

List
   
     newSkuIdList = skuIdList.stream().distinct().skip((currentPage - 1) * pageSize).limit(pageSize).collect(Collectors.toList());
   

Map
   
     openIdMap = list.stream()        .collect(Collectors.toMap(User::getUserId, User::getXcxOpenId));
   

这篇文章不错:

https://www.cnblogs.com/wenbronk/p/7300544.html

BigDecimal add = list.stream().map(User::getHeight).reduce(BigDecimal.ZERO, BigDecimal::add);

提取集合里的id集合：foodBasicList.stream()        .map(FoodBasic::getId).collect(Collectors.toList())

集合转map：foodBasicList.stream().collect(Collectors.toMap(FoodCountModel::getId, FoodCountModel::getSoldCount))

BigDecimal yearSaleMoney = list.stream().filter(s -> s.getNum() == 0).collect(Collectors.toList()).get(0).getSaleMoney();

List
   
     newAddressList = addressList.stream().map(s -> Long.valueOf(s)).collect(Collectors.toList());
   

java8 list统计（求和、最大、最小、平均）:

//2.根据拼团商品的排序规则,排序商品sortList.stream().forEach(s -> foodBasicList.stream()        .filter(y -> s.equals(String.valueOf(y.getId()))).forEach(f -> fBasicList.add(f)));//或者是下面的方法//        sortList.stream().forEach(item -> {//            foodBasicList.stream().forEach(y -> {//                if (Long.valueOf(item) == y.getId()) {//                    fBasicList.add(y);//                }//            });//        });JDK1.8对List指定字段进行排序：

java.util.Objects.equals(k, "E")java.util.Objects.nonNull(map)