Spring WebFlux Flux 和Mono区别

import reactor.core.publisher.Flux;
import reactor.core.publisher.Mono;
// --- Mono 示例 ---
// 1. 发出一个值
Mono<String> singleName = Mono.just("Alice");
singleName.subscribe(name -> System.out.println("Hello, " + name)); // 输出: Hello, Alice
// 2. 可能发出一个值，也可能为空
Mono<String> possiblyEmpty = Mono.justOrEmpty(getUserNameFromDatabase()); // 如果getUserNameFromDatabase()返回null，则Mono为空
possiblyEmpty
    .defaultIfEmpty("Guest") // 如果为空，则使用默认值
    .subscribe(name -> System.out.println("User: " + name));
// 3. 表示一个无返回值的操作 (如保存)
Mono<Void> saveOperation = saveUserToDatabase(user);
saveOperation
    .then(Mono.just("User saved successfully")) // 操作完成后，发出成功消息
    .subscribe(message -> System.out.println(message));
// --- Flux 示例 ---
// 1. 发出多个值
Flux<String> names = Flux.just("Alice", "Bob", "Charlie");
names.subscribe(name -> System.out.println("Name: " + name)); // 输出三行
// 2. 从集合创建
List<String> nameList = Arrays.asList("David", "Eve", "Frank");
Flux<String> namesFromList = Flux.fromIterable(nameList);
namesFromList.subscribe(System.out::println);
// 3. 处理数据库查询返回的多条记录
Flux<User> users = userRepository.findAll(); // 假设返回Flux<User>
users
    .filter(user -> user.getAge() > 18)
    .map(User::getName)
    .collectList() // 将所有名字收集到一个List中
    .subscribe(adultNames -> System.out.println("Adults: " + adultNames));
// 4. 事件流 (概念性)
Flux<String> eventStream = getWebSocketMessageFlux(); // 持续接收消息
eventStream.subscribe(message -> System.out.println("Received: " + message));