@Configuration
@Role(BeanDefinition.ROLE_INFRASTRUCTURE)
public class ProxyAsyncConfiguration extends AbstractAsyncConfiguration {@Bean(name = TaskManagementConfigUtils.ASYNC_ANNOTATION_PROCESSOR_BEAN_NAME)@Role(BeanDefinition.ROLE_INFRASTRUCTURE)public AsyncAnnotationBeanPostProcessor asyncAdvisor() {Assert.notNull(this.enableAsync, "@EnableAsync annotation metadata was not injected");AsyncAnnotationBeanPostProcessor bpp = new AsyncAnnotationBeanPostProcessor();Class<? extends Annotation> customAsyncAnnotation = this.enableAsync.getClass("annotation");if (customAsyncAnnotation != AnnotationUtils.getDefaultValue(EnableAsync.class, "annotation")) {bpp.setAsyncAnnotationType(customAsyncAnnotation);}if (this.executor != null) {bpp.setExecutor(this.executor);}if (this.exceptionHandler != null) {bpp.setExceptionHandler(this.exceptionHandler);}bpp.setProxyTargetClass(this.enableAsync.getBoolean("proxyTargetClass"));bpp.setOrder(this.enableAsync.<Integer>getNumber("order"));return bpp;}}

    @Autowired(required = false)void setConfigurers(Collection<AsyncConfigurer> configurers) {if (CollectionUtils.isEmpty(configurers)) {return;}if (configurers.size() > 1) {throw new IllegalStateException("Only one AsyncConfigurer may exist");}AsyncConfigurer configurer = configurers.iterator().next();this.executor = configurer.getAsyncExecutor();this.exceptionHandler = configurer.getAsyncUncaughtExceptionHandler();}

public class AsyncDefaultAutoConfiguration {@Autowired private BeanFactory beanFactory;@Configuration@ConditionalOnMissingBean(AsyncConfigurer.class)@ConditionalOnProperty(value = "spring.sleuth.async.configurer.enabled", matchIfMissing = true)static class DefaultAsyncConfigurerSupport extends AsyncConfigurerSupport {@Autowired private BeanFactory beanFactory;@Overridepublic Executor getAsyncExecutor() {return new LazyTraceExecutor(this.beanFactory, new SimpleAsyncTaskExecutor());}}