I am learning Spring WebFlux.

My Entity goes like this:

@Table("users")
public class User {
    @Id
    private Integer id;
    private String name;
    private int age;
    ,spring,h2,spring-webflux,r2dbc"/>
	














    

		

        

            
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首页  > 解决方案 > Spring WebFlux - 将 Flux 转换为 List

I am learning Spring WebFlux.


My Entity goes like this:


@Table("users")
public class User {
    @Id
    private Integer id;
    private String name;
    private int age;
    












spring - Spring WebFlux - 将 Flux 转换为 List

I am learning Spring WebFlux.


My Entity goes like this:


@Table("users")
public class User {
    @Id
    private Integer id;
    private String name;
    private int age;
    





问题描述



I am learning Spring WebFlux.


My Entity goes like this:


@Table("users")
public class User {
    @Id
    private Integer id;
    private String name;
    private int age;
    private double salary;
}



I have a Repository (R2 using H2 Database) like below:


public interface UserRepository extends ReactiveCrudRepository<User,Integer> {
   
}



And my controller is:


    @Autowired
    private UserRepository userRepository;

    private static List<User> userList = new ArrayList<>();

    @PostConstruct
    public void initializeStockObjects() {
        User stock1 = new User(11, "aaaa", 123, 123);
        User stock2 = new User(12, "bbb", 123, 123);
        User stock3 = new User(13, "ccc", 123, 123);
        userList.add(stock1);
        userList.add(stock2);
        userList.add(stock3);
    }

    @RequestMapping(value = "/livelistofusers", method = RequestMethod.GET, produces = MediaType.TEXT_EVENT_STREAM_VALUE)
    public Flux<List<User>> getUsers() {
        return getUserData(userList);
    }

    public Flux<List<User>> getUserData(List<User> userList) {
       Flux<Long> interval = Flux.interval(Duration.ofSeconds(3));
       interval.subscribe((i) -> userList.forEach(user -> addNewUser(user)));
       Flux<List<User>> transactionFlux = Flux.fromStream(Stream.generate(() -> userList));
       return Flux.zip(interval, transactionFlux).map(Tuple2::getT2);
     }



All good till this point. I am able to return the the entire list of users every 3 seconds to the view. No issues at all here.


Now, I want to send the Flue i.e. Flux flux2 = userRepository.findAll() to the view. That means, instead of return getUserData(userList); how can I do  return getUserData(flux2(...what should I do here ???... I tried couple of things but I end up making the Blocking list instead of Non-Blocking ...)); ?


Question: How can I achieve this? i.e. How can I send the entire Flux every 3 seconds to my view. I am feeling lost here and clueless. Any relevant help links or solution will be greatly appreciated.


Edit:


As per Nipuna's comments I tried this:


@RequestMapping(value = "/livelistofusersall", method = RequestMethod.GET, produces = MediaType.TEXT_EVENT_STREAM_VALUE)
    public Flux<List<User>>  getUsersall() {
        Flux<Long> interval = Flux.interval(Duration.ofSeconds(3));
        interval.subscribe((i) -> userRepository.findAll());
        Flux<List<User>> transactionFlux = userRepository.findAll().collectList().flatMapMany(Flux::just);
        return Flux.zip(interval, transactionFlux).map(Tuple2::getT2);
    }



But now at my context path, the list loads but "only once" after a wait of 3 seconds. What I am missing here?









You can use collectList() operator in Flux for this which gives a Mono of List.


userRepository.findAll().collectList().flatMapMany(Flux::just);



标签： springh2spring-webfluxr2dbc


解决方案









您可以collectList()在 Flux 中使用运算符，这会给出列表的 Mono。


userRepository.findAll().collectList().flatMapMany(Flux::just);











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