spring - 在 Spring 中使用 @Async 的 @EventListener

Question

尝试结合 @Async 和 @EventListener 注释启用异步事件处理，但我仍然看到监听器正在发布线程中运行。

您可以在此处找到示例:

@SpringBootApplication
@EnableAsync
class AsyncEventListenerExample {

static final Logger logger = LoggerFactory.getLogger(AsyncEventListenerExample.class);

@Bean
TaskExecutor taskExecutor() {
    return new SimpleAsyncTaskExecutor();
}


static class MedicalRecordUpdatedEvent {

    private String id;

    public MedicalRecordUpdatedEvent(String id) {
        this.id = id;
    }

    @Override
    public String toString() {
        return "MedicalRecordUpdatedEvent{" +
                "id='" + id + '\'' +
                '}';
    }
}

@Component
static class Receiver {

    @EventListener
    void handleSync(MedicalRecordUpdatedEvent event) {
        logger.info("thread '{}' handling '{}' event", Thread.currentThread(), event);
    }

    @Async
    @EventListener
    void handleAsync(MedicalRecordUpdatedEvent event) {
        logger.info("thread '{}' handling '{}' event", Thread.currentThread(), event);
    }

}

@Component
static class Producer {

    private final ApplicationEventPublisher publisher;

    public Producer(ApplicationEventPublisher publisher) {
        this.publisher = publisher;
    }

    public void create(String id) {
        publisher.publishEvent(new MedicalRecordUpdatedEvent(id));
    }

    @Async
    public void asynMethod() {
        logger.info("running async method with thread '{}'", Thread.currentThread());
    }
}

}

还有我的测试用例:

@RunWith(SpringRunner.class)
@SpringBootTest(classes = AsyncEventListenerExample.class)
public class AsyncEventListenerExampleTests {

@Autowired
Producer producer;

@Test
public void createEvent() throws InterruptedException {

    producer.create("foo");

    //producer.asynMethod();


    // A chance to see the logging messages before the JVM exists.
    Thread.sleep(2000);

}
}

但是在日志中我看到两个 @EventListener 都在 main 线程中运行。

2016-05-12 08:52:43.184  INFO 18671 --- [           main] c.z.e.async2.AsyncEventListenerExample   : thread 'Thread[main,5,main]' handling 'MedicalRecordUpdatedEvent{id='foo'}' event
2016-05-12 08:52:43.186  INFO 18671 --- [           main] c.z.e.async2.AsyncEventListenerExample   : thread 'Thread[main,5,main]' handling 'MedicalRecordUpdatedEvent{id='foo'}' event

async 基础结构使用 @EnableAsync 和异步 TaskExecutor 进行初始化。

不知道我做错了什么。你能帮忙吗？

谢谢。

使用 Spring Boot 1.4.2.M2，所以 Spring 4.3.0.RC1

Answer 1

Spring Framework 4.3.0.RC1 中有一个回归导致您遇到的问题。如果您使用 SNAPSHOT，您的项目运行良好。