Stream的终结方法

2201_757830872025-11-23 18:50

1.forEach

java 复制代码

ArrayList<String> list1 = new ArrayList<>();
        Collections.addAll(list1,"张无忌","周芷若","赵敏","张强","张三丰","张翠山","张良");
        list1.stream().forEach(s-> System.out.print(s+" "));

2.count

java 复制代码

ArrayList<String> list1 = new ArrayList<>();
        Collections.addAll(list1,"张无忌","周芷若","赵敏","张强","张三丰","张翠山","张良");
        long count = list1.stream().count();
        System.out.println(count);

3.toArray

java 复制代码

String[] arr2 = list1.stream().toArray(value -> new String[value]);
        System.out.println(Arrays.toString(arr2));

4.collect

java 复制代码

ArrayList<String> list1 = new ArrayList<>();
        Collections.addAll(list1,"张无忌-男-15","张无忌-男-15","周芷若-女-14","赵敏-女-13","张强-男-20","张三丰-男-100","张翠山-男-40","张良-男-35");
        List<String> list2 = list1.stream().filter(s -> "男".equals(s.split("-")[1]))
                .collect(Collectors.toList());
        System.out.println(list2);

        Set<String> list3 = list1.stream().filter(s -> "男".equals(s.split("-")[1]))
                .collect(Collectors.toSet());
        System.out.println(list3);

5.toMap:

java 复制代码

Map<String, String> map = list1.stream().filter(s -> "男".equals(s.split("-")[1])).
                collect(Collectors.toMap(
                        s -> s.split("-")[0],
                        s -> s.split("-")[2]));
        System.out.println(map);

详解：