springboot webflux flux 使用示例（轉換操作）

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springboot webflux flux 使用示例（轉換操作）

 

 

**********************

flatMap、map、transform、switchMap

 

class Person{

    private String name;
    private Integer age;

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public Integer getAge() {
        return age;
    }

    public void setAge(Integer age) {
        this.age = age;
    }

    @Override
    public boolean equals(Object o) {
        if (this == o) return true;
        if (!(o instanceof Person)) return false;
        Person person = (Person) o;
        return Objects.equals(getName(), person.getName()) &&
                Objects.equals(getAge(), person.getAge());
    }

    @Override
    public int hashCode() {
        return Objects.hash(getName(), getAge());
    }

    @Override
    public String toString() {
        return "Person{" +
                "name='" + name + '\'' +
                ", age=" + age +
                '}';
    }
}

public class Test {

    public static void main(String[] args){
        Map<String,String> map=new HashMap<>();
        map.put("name","瓜田李下");
        map.put("age","20");

        Flux.just(map).flatMap(m -> {
            String name=m.get("name");
            Integer age=Integer.parseInt(m.get("age"));

            Person person=new Person();
            person.setName(name);
            person.setAge(age);

            return Flux.just(person);
        }).subscribe(System.out::println);

        Flux.just(map).map(m -> {
            String name=m.get("name");
            Integer age=Integer.parseInt(m.get("age"));

            Person person=new Person();
            person.setName(name);
            person.setAge(age);

            return person;
        }).subscribe(System.out::println);

        Flux.just(map).transform(flux -> flux.flatMap(m -> {
            String name=m.get("name");
            Integer age=Integer.parseInt(m.get("age"));

            Person person=new Person();
            person.setName(name);
            person.setAge(age);

            return Flux.just(person);
        })).subscribe(System.out::println);

        Flux.just(map).transform(flux -> flux.map(m -> {
            String name=m.get("name");
            Integer age=Integer.parseInt(m.get("age"));

            Person person=new Person();
            person.setName(name);
            person.setAge(age);

            return person;
        })).subscribe(System.out::println);

        Flux.just(map).switchMap(m -> {
            String name=m.get("name");
            Integer age=Integer.parseInt(m.get("age"));

            Person person=new Person();
            person.setName(name);
            person.setAge(age);

            return Flux.just(person);
        }).subscribe(System.out::println);
    }
}

 

******************

控制檯輸出

 

Person{name='瓜田李下', age=20}
Person{name='瓜田李下', age=20}
Person{name='瓜田李下', age=20}
Person{name='瓜田李下', age=20}
Person{name='瓜田李下', age=20}

 

 

**********************

toIterable、toStream

 

public class Test2 {

    public static void main(String[] args){
        Flux.just("瓜田李下","瓜田李下 2","瓜田李下 3","瓜田李下 4","瓜田李下 5","瓜田李下 6")
                .toIterable().forEach(System.out::println);

        Flux.just("1 ","2 ","3 ","4 ","5 ","6 ").toStream().forEach(System.out::print);

        System.out.println("\n\n************");
        String s=Flux.just("瓜田李下","瓜田李下 2").elementAt(0)
                .flux().toIterable().iterator().next();
        System.out.println("flux 第0個元素爲："+s);

        String s2=Flux.just("hello world","hello world 2","hello world 3").last()
                .flux().toIterable().iterator().next();
        System.out.println("flux 最後一個元素爲："+s2);
    }
}

 

******************

控制檯輸出

 

瓜田李下
瓜田李下 2
瓜田李下 3
瓜田李下 4
瓜田李下 5
瓜田李下 6
1 2 3 4 5 6 

************
flux 第0個元素爲：瓜田李下
flux 最後一個元素爲：hello world 3

 

 

**********************

collect 

 

public class Test3 {

    public static void main(String[] args){
        Flux.just(2,34,56,75,4,56).collectList()
                .subscribe(list -> list.forEach(value -> System.out.print(value+"  ")));

        System.out.println();
        Flux.just(2,34,56,75,4,56).collectSortedList()
                .subscribe(list -> list.forEach(value -> System.out.print(value+"  ")));

        System.out.println("\n\n****************");
        Flux.just("1 瓜田李下","2 瓜田李下2","3 瓜田李下3").collectMap(
                value -> {
                    String[] s= value.split(" ");
                    return s[0];
                },
                value -> {
                    String[] s= value.split(" ");
                    return s[1];
                }
        ).subscribe(map -> map.forEach((key, value1) -> System.out.println(key + "  " + value1)));

        System.out.println("\n****************");
        Flux.just("1 瓜田李下 瓜田李下2 瓜田李下3 瓜田李下4 瓜田李下5 瓜田李下6",
                "2 hello hello2 hello3 hello4 hello5 hello6")
                .collectMultimap(
                        value -> {
                            String[] s=value.split(" ");
                            return s[0];
                            },
                        value -> {
                            String[] s=value.split(" ");

                            List<String> list=new ArrayList<>();
                            if (s.length>1) {
                                list.addAll(Arrays.asList(s).subList(1, s.length));
                            }

                            return list;
                        }).subscribe(map -> map.forEach((key,value) -> System.out.println(key+"  "+value)));
    }
}

 

******************

控制檯輸出

 

2  34  56  75  4  56  
2  4  34  56  56  75  

****************
1  瓜田李下
2  瓜田李下2
3  瓜田李下3

****************
1  [[瓜田李下, 瓜田李下2, 瓜田李下3, 瓜田李下4, 瓜田李下5, 瓜田李下6]]
2  [[hello, hello2, hello3, hello4, hello5, hello6]]