SpringBoot中依赖循环问题的产生与解决方案

@Service
public class UserService {

    private final OrderService orderService;

    public UserService(OrderService orderService) {
        this.orderService = orderService;
    }

    public void handleUser() {
        System.out.println("Handling user...");
        orderService.checkOrders();
    }
}

@Service
public class OrderService {

    private final UserService userService;

    public OrderService(UserService userService) {
        this.userService = userService;
    }

    public void checkOrders() {
        System.out.println("Checking orders...");
        userService.handleUser(); // 实际中可能不是直接调用，但存在依赖关系
    }
}

Error creating bean with name 'userService': Requested bean is currently in creation: Is there an unresolvable circular reference?

@Service
public class UserValidator {
    public boolean isValid(Long userId) {
        // 验证逻辑
        return true;
    }
}

@Service
public class UserService {
    private final UserValidator userValidator;

    public UserService(UserValidator userValidator) {
        this.userValidator = userValidator;
    }

    public void handleUser() {
        System.out.println("Handling user...");
    }
}

@Service
public class OrderService {
    private final UserValidator userValidator;

    public OrderService(UserValidator userValidator) {
        this.userValidator = userValidator;
    }

    public void checkOrders() {
        if (userValidator.isValid(1L)) {
            System.out.println("Orders are valid.");
        }
    }
}

@Service
public class UserService {

    private final OrderService orderService;

    public UserService(@Lazy OrderService orderService) {
        this.orderService = orderService;
    }

    // ...
}

@Service
public class UserService {

    @Autowired
    private OrderService orderService;

    // ...
}

@Component
public class ServiceLocator implements ApplicationContextAware {

    private static ApplicationContext context;

    @Override
    public void setApplicationContext(ApplicationContext applicationContext) {
        ServiceLocator.context = applicationContext;
    }

    public static <T> T getBean(Class<T> clazz) {
        return context.getBean(clazz);
    }
}

// 在 UserService 中
public void someMethod() {
    OrderService orderService = ServiceLocator.getBean(OrderService.class);
    orderService.doSomething();
}