钩子

一、事件监听

// 定义订单创建事件
public class OrderCreatedEvent extends ApplicationEvent {
    public OrderCreatedEvent(Object source) {
        super(source);
    }
}

// 监听订单创建事件的监听器
@Component
public class OrderCreatedEventListener implements ApplicationListener<OrderCreatedEvent> {
    @Override
    public void onApplicationEvent(OrderCreatedEvent event) {
        // 在这里执行订单创建后的逻辑
        System.out.println("Order Created Event Received. Processing...");
    }
}

// 触发订单创建事件的业务逻辑
@Service
public class OrderService {
    @Autowired
    private ApplicationEventPublisher eventPublisher;

    public void createOrder() {
        // 创建订单的业务逻辑...

        // 发布订单创建事件
        eventPublisher.publishEvent(new OrderCreatedEvent(this));
    }
}

二、拦截器

public class AuthInterceptor implements HandlerInterceptor {
    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
        // 在这里执行权限验证逻辑
        if (/* 用户没有权限 */) {
            response.sendError(HttpServletResponse.SC_FORBIDDEN, "Access Denied");
            return false;
        }
        return true;
    }
}

// 配置拦截器
@Configuration
public class WebConfig implements WebMvcConfigurer {
    @Autowired
    private AuthInterceptor authInterceptor;

    @Override
    public void addInterceptors(InterceptorRegistry registry) {
        registry.addInterceptor(authInterceptor);
    }
}

三、切面

@Aspect
@Component
public class LoggingAspect {

    @Before("execution(* com.example.service.*.*(..))")
    public void logBeforeMethodExecution(JoinPoint joinPoint) {
        // 在方法执行前记录日志
        System.out.println("Method execution started: " + joinPoint.getSignature().toShortString());
    }

    @After("execution(* com.example.service.*.*(..))")
    public void logAfterMethodExecution(JoinPoint joinPoint) {
        // 在方法执行后记录日志
        System.out.println("Method execution completed: " + joinPoint.getSignature().toShortString());
    }
}