28

在 Spring MVC 应用程序中，我有一个请求范围的 bean。我在某处注入了这个 bean。在那里，HTTP 请求服务线程可能会产生一个新线程。

但是每当我尝试从新生成的线程访问请求范围的 bean 时，我都会得到一个org.springframework.beans.factory.BeanCreationException（参见下面的堆栈跟踪）。
从 HTTP 请求线程访问请求范围的 bean 工作正常。

如何使 HTTP 请求线程产生的线程可以使用请求范围的 bean？

简单的设置

运行以下代码片段。然后启动服务器，例如http://example.com:8080。
访问http://example.com:8080/scopetestnormal时，每次对该地址发出请求时，counter都会增加 1（通过记录器输出可见）。：） 极好的！

访问http://example.com:8080/scopetestthread时，每次向该地址发出请求时，都会抛出上述异常。:(。无论选择什么ScopedProxyMode，这都会发生在基于 CGLIB 和基于JDK -dynamic-proxy-interface-interface 的请求范围 bean 上

配置文件

package com.example.config

@Configuration
@ComponentScan(basePackages = { "com.example.scopetest" })
public class ScopeConfig {

    private Integer counter = new Integer(0);

    @Bean
    @Scope(value = "request", proxyMode = ScopedProxyMode.TARGET_CLASS)
    public Number counter() {
        counter = new Integer(counter.intValue() + 1);
        return counter;
    }


    /* Adding a org.springframework.social.facebook.api.Facebook request-scoped bean as a real-world example why all this matters
    @Bean
    @Scope(value = "request", proxyMode = ScopedProxyMode.INTERFACES)
    public Facebook facebook() {
    Connection<Facebook> facebook = connectionRepository()
            .findPrimaryConnection(Facebook.class);
    return facebook != null ? facebook.getApi() : new FacebookTemplate();
    }
    */

    ...................

}

控制器文件

package com.example.scopetest;

import javax.inject.Inject;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import org.springframework.social.facebook.api.Facebook;
import org.springframework.social.facebook.api.FacebookProfile;
import org.springframework.stereotype.Controller;

import org.springframework.web.bind.annotation.RequestMapping;

@Controller
public class ScopeTestController {

    //@Inject
    //private Facebook facebook;

    @Inject
    private Number counter;

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

    @RequestMapping(value = "/scopetestnormal") 
    public void scopetestnormal() {
        logger.debug("About to interact with a request-scoped bean from HTTP request thread");
        logger.debug("counter is: {}", counter);

        /* 
         * The following also works
         * FacebookProfile profile = facebook.userOperations().getUserProfile();
         * logger.debug("Facebook user ID is: {}", profile.getId());    
         */
    }



    @RequestMapping(value = "/scopetestthread")
    public void scopetestthread() {
        logger.debug("About to spawn a new thread");
        new Thread(new RequestScopedBeanAccessingThread()).start();
        logger.debug("Spawned a new thread");
    }


    private class RequestScopedBeanAccessingThread implements Runnable {

        @Override
        public void run() {
            logger.debug("About to interact with a request-scoped bean from another thread. Doomed to fail.");          
            logger.debug("counter is: {}", counter);

            /*
             * The following is also doomed to fail
             * FacebookProfile profile = facebook.userOperations().getUserProfile();
             * logger.debug("Facebook user ID is: {}", profile.getId());        
             */
        }

    }

}

基于 CGLIB 的请求范围 bean ( proxyMode = ScopedProxyMode.TARGET_CLASS)的堆栈跟踪

SLF4J: Failed toString() invocation on an object of type [$java.lang.Number$$EnhancerByCGLIB$$45ffcde7]
org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'scopedTarget.counter': Scope 'request' is not active for the current thread; consider defining a scoped proxy for this bean if you intend to refer to it from a singleton; nested exception is java.lang.IllegalStateException: No thread-bound request found: Are you referring to request attributes outside of an actual web request, or processing a request outside of the originally receiving thread? If you are actually operating within a web request and still receive this message, your code is probably running outside of DispatcherServlet/DispatcherPortlet: In this case, use RequestContextListener or RequestContextFilter to expose the current request.
    at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:342)
    at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:193)
    at org.springframework.aop.target.SimpleBeanTargetSource.getTarget(SimpleBeanTargetSource.java:33)
    at org.springframework.aop.framework.Cglib2AopProxy$DynamicAdvisedInterceptor.getTarget(Cglib2AopProxy.java:654)
    at org.springframework.aop.framework.Cglib2AopProxy$DynamicAdvisedInterceptor.intercept(Cglib2AopProxy.java:605)
    at $java.lang.Number$$EnhancerByCGLIB$$45ffcde7.toString(<generated>)
    at org.slf4j.helpers.MessageFormatter.safeObjectAppend(MessageFormatter.java:304)
    at org.slf4j.helpers.MessageFormatter.deeplyAppendParameter(MessageFormatter.java:276)
    at org.slf4j.helpers.MessageFormatter.arrayFormat(MessageFormatter.java:230)
    at ch.qos.logback.classic.spi.LoggingEvent.<init>(LoggingEvent.java:114)
    at ch.qos.logback.classic.Logger.buildLoggingEventAndAppend(Logger.java:447)18:09:48.276 container [Thread-16] DEBUG c.g.s.c.c.god.ScopeTestController - counter is: [FAILED toString()]

    at ch.qos.logback.classic.Logger.filterAndLog_1(Logger.java:421)
    at ch.qos.logback.classic.Logger.debug(Logger.java:514)
    at com.example.scopetest.ScopeTestController$RequestScopedBeanAccessingThread.run(ScopeTestController.java:58)
    at java.lang.Thread.run(Thread.java:722)
Caused by: java.lang.IllegalStateException: No thread-bound request found: Are you referring to request attributes outside of an actual web request, or processing a request outside of the originally receiving thread? If you are actually operating within a web request and still receive this message, your code is probably running outside of DispatcherServlet/DispatcherPortlet: In this case, use RequestContextListener or RequestContextFilter to expose the current request.
    at org.springframework.web.context.request.RequestContextHolder.currentRequestAttributes(RequestContextHolder.java:131)
    at org.springframework.web.context.request.AbstractRequestAttributesScope.get(AbstractRequestAttributesScope.java:40)
    at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:328)
    ... 14 more

proxyMode = ScopedProxyMode.INTERFACESJDK-dynamic-proxy-interface-based request-scoped bean ( )的堆栈跟踪

Exception in thread "Thread-16" org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'scopedTarget.facebook': Scope 'request' is not active for the current thread; consider defining a scoped proxy for this bean if you intend to refer to it from a singleton; nested exception is java.lang.IllegalStateException: No thread-bound request found: Are you referring to request attributes outside of an actual web request, or processing a request outside of the originally receiving thread? If you are actually operating within a web request and still receive this message, your code is probably running outside of DispatcherServlet/DispatcherPortlet: In this case, use RequestContextListener or RequestContextFilter to expose the current request.
    at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:342)
    at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:193)
    at org.springframework.aop.target.SimpleBeanTargetSource.getTarget(SimpleBeanTargetSource.java:33)
    at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:182)
    at $Proxy28.userOperations(Unknown Source)
    at com.example.scopetest.ScopeTestController$PrintingThread.run(ScopeTestController.java:61)
    at java.lang.Thread.run(Thread.java:722)
Caused by: java.lang.IllegalStateException: No thread-bound request found: Are you referring to request attributes outside of an actual web request, or processing a request outside of the originally receiving thread? If you are actually operating within a web request and still receive this message, your code is probably running outside of DispatcherServlet/DispatcherPortlet: In this case, use RequestContextListener or RequestContextFilter to expose the current request.
    at org.springframework.web.context.request.RequestContextHolder.currentRequestAttributes(RequestContextHolder.java:131)
    at org.springframework.web.context.request.AbstractRequestAttributesScope.get(AbstractRequestAttributesScope.java:40)
    at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:328)
    ... 6 more
4

5 回答 5

10

好的，通过阅读Spring 附带的SimpleThreadScope中的代码，我认为您可以改为使用InheritableThreadLocal创建 SimpleInheritableThreadScope 。

然后只需使用一些 xml 来注册您的自定义范围：

<bean class="org.springframework.beans.factory.config.CustomScopeConfigurer">
      <property name="scopes">
          <map>
              <entry key="thread-inherited">
                  <bean class="org.mael.spring.context.support.SimpleInheritableThreadScope"/>
              </entry>
          </map>
      </property>
  </bean>

这意味着当您创建一个具有thread-inherited范围的 bean 时，您将可以使用每个线程的副本访问该 bean，并且该副本将在您的线程产生的线程中可用，即可以在您的线程中产生的线程中使用的请求范围 bean请求线程。

于 2013-02-20T18:32:40.933 回答
8

下面的配置会将请求上下文传播到从 HTTP 请求中启动的线程：

<servlet>
    <servlet-name>Spring MVC Dispatcher Servlet</servlet-name>
    <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
    <init-param>
      <param-name>threadContextInheritable</param-name>
      <param-value>true</param-value>
    </init-param>
    <load-on-startup>1</load-on-startup>
</servlet>

免责声明：我没有使用请求范围的 bean 专门对此进行测试，因为我不使用任何。我确实测试过 RequestContextHolder 在子线程中返回有效的上下文。

免责声明 2：此设置默认为 false 是有原因的。可能会有副作用，特别是如果您重用线程（如在线程池中）。

于 2013-02-20T19:50:17.257 回答
6

如果您看一下，AbstractRequestAttributesScope您会发现它正在使用电流RequestAttributes来获取所需的 bean。

在您的线程中，您可能想要执行以下操作：

final RequestAttributes requestAttributes = RequestContextHolder.getRequestAttributes();
final SecurityContext securityContext = SecurityContextHolder.getContext();

new Thread(
    () -> {

      boolean hasContext = RequestContextHolder.getRequestAttributes() == requestAttributes
          && SecurityContextHolder.getContext() == securityContext;

      if (!hasContext) {
        RequestContextHolder.setRequestAttributes(requestAttributes);
        SecurityContextHolder.setContext(securityContext);
      }

      try {

        // useful stuff goes here

      } finally {
        if (!hasContext) {
          RequestContextHolder.resetRequestAttributes();
          SecurityContextHolder.clearContext();
        }
      }
    }
).start();
于 2016-06-24T11:24:24.833 回答
4

受@mael 回答的启发，这是我的“custom-scope-out-of-the-box”解决方案。我正在使用完全由注释驱动的 Spring 配置。

对于我的特殊情况，Spring 自己的org.springframework.context.support.SimpleThreadScope已经提供了问题正在寻找的行为（对，这很奇怪，因为SimpleThreadScope不使用 a InheritableThreadLocal，但实际上是 a ThreadLocal。但是当它起作用时，我已经很高兴了）。

尚未测试并发用户交互时的正确行为。

脚步

注册SimpleThreadScope类型：

package com.example.config

public class MainConfig implements BeanFactoryAware {

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

    .......

    @Override
    public void setBeanFactory(BeanFactory beanFactory) throws BeansException {
        if (beanFactory instanceof ConfigurableBeanFactory) {

            logger.info("MainConfig is backed by a ConfigurableBeanFactory");
            ConfigurableBeanFactory cbf = (ConfigurableBeanFactory) beanFactory;

            /*Notice:
             *org.springframework.beans.factory.config.Scope
             * !=
             *org.springframework.context.annotation.Scope
             */
            org.springframework.beans.factory.config.Scope simpleThreadScope = new SimpleThreadScope();
            cbf.registerScope("simpleThreadScope", simpleThreadScope);

            /*why the following? Because "Spring Social" gets the HTTP request's username from
             *SecurityContextHolder.getContext().getAuthentication() ... and this 
             *by default only has a ThreadLocal strategy...
             *also see http://stackoverflow.com/a/3468965/923560 
             */
            SecurityContextHolder.setStrategyName(SecurityContextHolder.MODE_INHERITABLETHREADLOCAL);

        }
        else {
            logger.info("MainConfig is not backed by a ConfigurableBeanFactory");
        } 
    }
}

现在对于任何具有请求范围并且可以从 HTTP 请求线程产生的任何线程使用的 bean，相应地设置新定义的范围：

package com.example.config

@Configuration
@ComponentScan(basePackages = { "com.example.scopetest" })
public class ScopeConfig {

    private Integer counter = new Integer(0);

    @Bean
    @Scope(value = "simpleThreadScope", proxyMode = ScopedProxyMode.TARGET_CLASS)
    public Number counter() {
        counter = new Integer(counter.intValue() + 1);
        return counter;
    }


    @Bean
    @Scope(value = "simpleThreadScope", proxyMode = ScopedProxyMode.INTERFACES)
    public ConnectionRepository connectionRepository() {
        Authentication authentication = SecurityContextHolder.getContext().getAuthentication();
        if (authentication == null) {
            throw new IllegalStateException("Unable to get a ConnectionRepository: no user signed in");
        }
        return usersConnectionRepository().createConnectionRepository(authentication.getName());
    }


    @Bean
    @Scope(value = "simpleThreadScope", proxyMode = ScopedProxyMode.INTERFACES)
    public Facebook facebook() {
    Connection<Facebook> facebook = connectionRepository().findPrimaryConnection(Facebook.class);
    return facebook != null ? facebook.getApi() : new FacebookTemplate();
    }


    ...................

}
于 2013-02-20T23:32:20.427 回答
4

https://stackoverflow.com/a/30640097/2569475

对于这个问题，请检查我在上面给出的 url 的回答

Using a request scoped bean outside of an actual web request. If you use a Servlet 2.5 web container, with requests processed outside of Spring’s DispatcherServlet (for example, when using JSF or Struts), you need to register the org.springframework.web.context.request.RequestContextListener ServletRequestListener. For Servlet 3.0+, this can done programmatically via the WebApplicationInitializer interface. Alternatively, or for older containers, add the following declaration to your web application’s web.xml file:

于 2015-06-17T07:16:59.683 回答