Spring Boot 监听器Listeners详细教程(最新整理)

public class OrderCreateEvent extends ApplicationEvent {
    private String orderId;
    public OrderCreateEvent(Object source, String orderId) {
        super(source);
        this.orderId = orderId;
    }
    public String getOrderId() {
        return orderId;
    }
}

@Service
public class OrderService {
    @Autowired
    private ApplicationEventPublisher eventPublisher;
    public void createOrder(Order order) {
        // 创建订单逻辑...
        eventPublisher.publishEvent(new OrderCreateEvent(this, order.getId()));
    }
}

import org.springframework.boot.context.event.ApplicationReadyEvent;
import org.springframework.context.ApplicationListener;
public class SystemStartupListener implements ApplicationListener<ApplicationReadyEvent> {
    @Override
    public void onApplicationEvent(ApplicationReadyEvent event) {
        System.out.println("=== 应用启动完成，执行初始化操作 ===");
        // 初始化业务数据...
    }
}

public class OrderCreateEventListener implements ApplicationListener<OrderCreateEvent> {
    @Override
    public void onApplicationEvent(OrderCreateEvent event) {
        System.out.println("=== 执行操作 ===");
        // 初始化业务数据...
    }
}

import org.springframework.context.event.EventListener;
import org.springframework.boot.context.event.ApplicationStartedEvent;
@Component
public class AnnotationBasedListener {
    @EventListener
    public void handleStartedEvent(ApplicationStartedEvent event) {
        System.out.println("=== 应用启动事件捕获 ===");
    }
}

@Component
public class AnnotationBasedListener {
    @EventListener
    public void handleStartedEvent(OrderCreateEvent event) {
        System.out.println("=== 执行操作 ===");
    }
}

@Slf4j
@Component
public class MyTask implements SmartApplicationListener {
    @Override
    public boolean supportsEventType(Class<? extends ApplicationEvent> eventType) {
        return eventType == MyEvent.class || eventType == OrderCreateEvent.class;
    }
    @Override
    public int getOrder() {
        return 0;
    }
    @Override
    public void onApplicationEvent(ApplicationEvent event) {
        if (event instanceof OrderCreateEvent) {
            log.info("监听到 OrderCreateEvent...");
        }
        if (event instanceof MyEvent) {
            log.info("监听到 MyEvent...");
            MyEvent myEvent = (MyEvent) event;
            System.out.println("时间：" + myEvent.getTime() + " 信息：" + myEvent.getMsg());
        }
    }
}

    @EventListener
    @Order(Ordered.HIGHEST_PRECEDENCE) // 最高优先级
    public void handleOrderEvent(OrderCreateEvent event) {
        System.out.println("收到订单创建事件，订单ID：" + event.getOrderId());
        // 发送通知、更新统计...
    }

@Configuration
@EnableAsync
public class AsyncConfig implements AsyncConfigurer {
    @Override
    public Executor getAsyncExecutor() {
        ThreadPoolTaskExecutor executor = new ThreadPoolTaskExecutor();
        executor.setCorePoolSize(5);
        executor.initialize();
        return executor;
    }
}
// 可进行如下替换
@EventListener
@Async
public void asyncHandleEvent(MyEvent event) {
    // 异步执行
}

@EventListener(condition = "#event.orderId.startsWith('VIP')")
public void handleVipOrder(OrderCreateEvent event) {
    // 只处理VIP订单
}