订阅功能用Springboot实现的代码

很抱歉，作为AI语言模型，我不具备编写代码的能力。但我可以向您展示一个简单的订阅功能的Spring Boot代码示例，您可以参考它进行开发和实现。

@RestController
@RequestMapping("/api")
public class SubscriptionController {

    @Autowired
    private SubscriptionService subscriptionService;

    @PostMapping("/subscribe")
    public ResponseEntity<?> subscribe(@RequestBody SubscriptionRequest request) {
        Subscription subscription = subscriptionService.createSubscription(request);
        return ResponseEntity.ok(subscription);
    }

    @GetMapping("/subscriptions")
    public ResponseEntity<?> getSubscriptions() {
        List<Subscription> subscriptions = subscriptionService.getSubscriptions();
        return ResponseEntity.ok(subscriptions);
    }

    @DeleteMapping("/unsubscribe/{id}")
    public ResponseEntity<?> unsubscribe(@PathVariable("id") Long id) {
        subscriptionService.cancelSubscription(id);
        return ResponseEntity.noContent().build();
    }
}

@Service
public class SubscriptionService {

    private List<Subscription> subscriptions = new ArrayList<>();

    public Subscription createSubscription(SubscriptionRequest request) {
        Subscription subscription = new Subscription(request.getEmail(), request.getFrequency());
        subscriptions.add(subscription);
        return subscription;
    }

    public List<Subscription> getSubscriptions() {
        return subscriptions;
    }

    public void cancelSubscription(Long id) {
        subscriptions.removeIf(subscription -> subscription.getId().equals(id));
    }
}

public class Subscription {

    private static Long counter = 0L;

    private Long id;
    private String email;
    private Frequency frequency;

    public Subscription(String email, Frequency frequency) {
        this.id = ++counter;
        this.email = email;
        this.frequency = frequency;
    }

    public Long getId() {
        return id;
    }

    public String getEmail() {
        return email;
    }

    public Frequency getFrequency() {
        return frequency;
    }

    public enum Frequency {
        DAILY, WEEKLY, MONTHLY
    }
}

public class SubscriptionRequest {

    private String email;
    private Subscription.Frequency frequency;

    public String getEmail() {
        return email;
    }

    public void setEmail(String email) {
        this.email = email;
    }

    public Subscription.Frequency getFrequency() {
        return frequency;
    }

    public void setFrequency(Subscription.Frequency frequency) {
        this.frequency = frequency;
    }
}

这个示例代码中，订阅功能包括三个操作：订阅、获取订阅列表和取消订阅。其中，订阅和取消订阅通过HTTP POST和DELETE请求实现，分别对应于`subscribe()`和`unsubscribe()`方法。`getSubscriptions()`方法则用于获取当前所有的订阅列表。

在代码中，我们定义了一个`Subscription`类用于表示订阅信息。每个订阅都有一个唯一的ID，一个邮箱地址和一个订阅频率。订阅频率是一个枚举类型，包括每日、每周和每月三种选项。

在`SubscriptionService`类中，我们定义了一些方法用于实现订阅功能。`createSubscription()`方法用于创建新的订阅，`getSubscriptions()`方法用于获取当前所有的订阅列表，`cancelSubscription()`方法用于取消某个订阅。

最后，在`SubscriptionRequest`类中，我们定义了一个请求对象，用于接收订阅请求中的参数：邮箱地址和订阅频率。在`subscribe()`方法中，我们根据请求参数创建新的订阅对象，并添加到订阅列表中。在`unsubscribe()`方法中，我们根据订阅的ID删除对应的订阅对象。