Spring异步事件机制

1、好处：解耦
2、Spring的事件机制默认是同步方式
3、@Async可以使用到类级别，也可以到方法级别

开启异步支持 @EnableAsync

@Configuration
@EnableAsync
public class AppCommonConfig implements AsyncConfigurer{
    @Override
    public Executor getAsyncExecutor() {
    	//TODO: 这里可以实现自己的线程池
        return null;
    }

    @Override
    public AsyncUncaughtExceptionHandler getAsyncUncaughtExceptionHandler() {
        return null;
    }
}

事件消费者

@Component
@Async
public class EventConsumer implements ApplicationListener {
    @Override
    public void onApplicationEvent(ApplicationEvent event) {
        logger.info("接收到事件：" + event.getClass().getSimpleName());
        if (event instanceof OrderEvent) {
            OrderEvent orderEvent = (OrderEvent) event;
            //TODO 后续逻辑
        } 
    }
}

事件生产者

public class XxxService implements ApplicationEventPublisherAware {

    //事件发布者
    protected ApplicationEventPublisher applicationEventPublisher;

    @Override
    public void setApplicationEventPublisher(ApplicationEventPublisher applicationEventPublisher) {
        this.applicationEventPublisher = applicationEventPublisher;
    }
          
    public void method11(){
         OrderEvent orderEvent = new OrderEvent(this, "data");
         applicationEventPublisher.publishEvent(orderEvent);
     }
}

事件对象

public class OrderEvent extends ApplicationEvent {
    private Object data;
    public OrderEvent(Object source, Object data) {
        super(source);
        this.data = data;
    }
    public Object getData() {
        return data;
    }
}

方式二：开启异步支持不实现AsyncConfigurer

@Configuration
@EnableAsync
public class AppCommonConfig {
    @Bean(name = "asyncExecutor")
    public Executor asyncExecutor()
    {
        ThreadPoolTaskExecutor executor = new ThreadPoolTaskExecutor();
        executor.setCorePoolSize(3);
        executor.setMaxPoolSize(3);
        executor.setQueueCapacity(100);
        executor.setThreadNamePrefix("AsynchThread-");
        executor.initialize();
        return executor;
    }
}

事件消费者

@Component
@Async("asyncExecutor") //线程池的bean名称
public class EventConsumer implements ApplicationListener {
    @Override
    public void onApplicationEvent(ApplicationEvent event) {
        logger.info("接收到事件：" + event.getClass().getSimpleName());
        if (event instanceof OrderEvent) {
            OrderEvent orderEvent = (OrderEvent) event;
            //TODO 后续逻辑
        } 
    }
}