从 4.2.0.RC3 升级到 4.2.0.RELEASE 时出现异常问题

java spring spring-mvc executorservice spring-websocket

2022-09-02 12:00:41

我有一个使用spring（4.2.x）工件spring-webmvc，spring-messaging，spring-websocket的Web应用程序

我在我的春季配置java类中有以下@Enable*注释

@EnableWebMvc
@EnableWebSocketMessageBroker
@EnableAsync
@EnableMBeanExport

WebSocket 用于将消息广播到浏览器客户端。而且很少有异步方法带有@Async

该应用程序在弹簧版本4.2.0.RC3中运行良好。但是当我将其更改为GA版本4.2.0.RELEASE时，我在启动时遇到了以下异常。如果我删除@EnableAsync它可以正常工作，但我需要异步功能。

org.springframework.beans.factory.NoUniqueBeanDefinitionException: No qualifying bean of type [org.springframework.core.task.TaskExecutor] is defined: expected single matching bean but found 4: clientOutboundChannelExecutor,messageBrokerTaskScheduler,clientInboundChannelExecutor,brokerChannelExecutor
    org.springframework.beans.factory.support.DefaultListableBeanFactory.getBean(DefaultListableBeanFactory.java:366)
    org.springframework.beans.factory.support.DefaultListableBeanFactory.getBean(DefaultListableBeanFactory.java:332)
    org.springframework.scheduling.annotation.AsyncAnnotationBeanPostProcessor.setBeanFactory(AsyncAnnotationBeanPostProcessor.java:128)
    org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.invokeAwareMethods(AbstractAutowireCapableBeanFactory.java:1597)
    org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1565)
    org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:545)
    org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:482)
    org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:305)
    org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:230)
    org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:301)
    org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:201)
    org.springframework.context.support.PostProcessorRegistrationDelegate.registerBeanPostProcessors(PostProcessorRegistrationDelegate.java:228)
    org.springframework.context.support.AbstractApplicationContext.registerBeanPostProcessors(AbstractApplicationContext.java:682)
    org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:522)
    org.springframework.web.servlet.FrameworkServlet.configureAndRefreshWebApplicationContext(FrameworkServlet.java:667)
    org.springframework.web.servlet.FrameworkServlet.initWebApplicationContext(FrameworkServlet.java:539)
    org.springframework.web.servlet.FrameworkServlet.initServletBean(FrameworkServlet.java:493)
    org.springframework.web.servlet.HttpServletBean.init(HttpServletBean.java:136)

答案 1

在 Spring 应用程序上下文配置中添加 Bean

@Configuration
@EnableAsync
public class AppContext extends WebMvcConfigurationSupport {
    @Bean
    public Executor taskExecutor() {
        return new SimpleAsyncTaskExecutor();
    }
}

我建议你参考 linuxism.tistory.com/2076

如果以 XML 格式声明执行器，则可以创建一个类并将其命名为 TaskExecutor。然后，当Spring试图找到TaskExecutor bean时，它会找到这个。

@Component
public class TaskExecutor extends SimpleAsyncTaskExecutor {
}

答案 2

必须实现之一来指定特定方法。@ConfigurationAsyncConfigurerTaskExecutor@Async

否则，它混淆了从中选择哪一个。applicationContext

即使它与它一起工作也无关紧要，因此该错误已被修复。RC3GA

更新

源代码中的内容如下：AsyncAnnotationBeanPostProcessor

Executor executorToUse = this.executor;
if (executorToUse == null) {
    try {
        // Search for TaskExecutor bean... not plain Executor since that would
        // match with ScheduledExecutorService as well, which is unusable for
        // our purposes here. TaskExecutor is more clearly designed for it.
        executorToUse = beanFactory.getBean(TaskExecutor.class);
    }
    catch (NoUniqueBeanDefinitionException ex) {
        try {
            executorToUse = beanFactory.getBean(DEFAULT_TASK_EXECUTOR_BEAN_NAME, TaskExecutor.class);
        }
        catch (NoSuchBeanDefinitionException ex2) {
            throw new IllegalStateException("More than one TaskExecutor bean exists within the context, " +
                    "and none is named 'taskExecutor'. Mark one of them as primary or name it " +
                    "'taskExecutor' (possibly as an alias); or specify the AsyncConfigurer interface " +
                    "and implement getAsyncExecutor() accordingly.", ex);
        }
    }
    catch (NoSuchBeanDefinitionException ex) {
        logger.debug("Could not find default TaskExecutor bean", ex);
        // Giving up -> falling back to default executor within the advisor...
    }
}

所以，我想在从RC3到GA之间，你已经在这个问题上有了一个豆豆。taskExecutor

正如我们所看到的，StackTrace已经有了这样的豆子......