Java Lambda 表达式高频用法

//collections 代表集合对象；array 代表数组对象
collections.stream().map(p -> p.get("id")).collect(Collectors.toList());
Arrays.stream(array).map(p -> p.get("id")).collect(Collectors.toSet());
collections.stream().collect(Collectors.toMap(k -> k.getLong("id"), v -> v, (A, B) -> A));//如果key重复则保留第一个key
Arrays.stream(array).collect(Collectors.toMap(k -> k.getLong("id"), v -> v, (A, B) -> A));
collections.stream().filter(p -> "success".equals(p.getString("tool"))).collect(Collectors.toList());//过滤出满足条件的
map.forEach((key, value) -> {System.out.println("Key: " + key + ", Value: " + value);}); //map对象读取数据
collections.sort(names, (s1, s2) -> s1.compareTo(s2));//排序
Map<Long, List<Object>> collection = Arrays.stream(array).collect(Collectors.groupingBy(p -> p.getLong("modeltype_id")));