webflux 小例子

    // 根据id查询
    public Mono<ServerResponse> getUserById(ServerRequest request) {
        Integer id = Integer.valueOf(request.pathVariable("id"));
        // 非空处理
        Mono<ServerResponse> notFound = ServerResponse.notFound().build();
        Mono<User> userMono = this.userService.getUserById(id);
        //把userMono 进行转换
        //使用Reactor 操作符flatMap
        return userMono
                .flatMap(user -> ServerResponse.ok().contentType(MediaType.APPLICATION_JSON).body(fromValue(user)))
                .switchIfEmpty(notFound);
    }

    @Override
    public Mono<Void> saveUserInfo(Mono<User> userMono) {
        return userMono.doOnNext(user -> {
            // 放到Map
            this.users.put(user.getId(), user);
        }).thenEmpty(Mono.empty());// 终止信号
    }

    @Override
    public Flux<User> getAllUser() {
        return Flux.fromIterable(this.users.values());
    }