如何在异步任务执行器中启用请求范围

Question

在我的应用程序中，我有一些异步Web服务。服务器接受请求，返回OK响应，并开始使用AsyncTaskExecutor处理请求。我的问题是如何在此处启用请求范围，因为在此处理中，我需要获取由以下内容注释的类：

@Scope(value = WebApplicationContext.SCOPE_REQUEST, proxyMode = ScopedProxyMode.TARGET_CLASS)

现在我得到异常：

org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'scopedTarget.requestContextImpl': 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.

因为它在SimpleAsyncTaskExecutor而不是在DispatcherServlet

我的请求异步处理

taskExecutor.execute(new Runnable() {

    @Override
    public void run() {
        asyncRequest(request);
    }
});

taskExecutor在哪里：

<bean id="taskExecutor" class="org.springframework.core.task.SimpleAsyncTaskExecutor" />

Answer 1

我们遇到了同样的问题-需要使用@Async在后台执行代码，因此它无法使用任何Session-或RequestScope bean。我们通过以下方式解决了它：

• 创建一个自定义TaskPoolExecutor，用于存储范围内的信息和任务
• 创建一个特殊的Callable（或Runnable），该信息使用该信息来设置和清除后台线程的上下文
• 创建替代配置以使用自定义执行程序
  注意：这仅适用于Session和Request作用域的bean，不适用于安全上下文（如Spring Security中一样）。如果您要这样做，则必须使用另一种方法来设置安全上下文。
  

注意2：为简便起见，仅显示Callable和Submit（）实现。您可以对Runnable和execute（）执行相同的操作。

这是代码：

Executor:

public class ContextAwarePoolExecutor extends ThreadPoolTaskExecutor {
    @Override
    public <T> Future<T> submit(Callable<T> task) {
        return super.submit(new ContextAwareCallable(task, RequestContextHolder.currentRequestAttributes()));
    }

    @Override
    public <T> ListenableFuture<T> submitListenable(Callable<T> task) {
        return super.submitListenable(new ContextAwareCallable(task, RequestContextHolder.currentRequestAttributes()));
    }
}

Callable:

public class ContextAwareCallable<T> implements Callable<T> {
    private Callable<T> task;
    private RequestAttributes context;

    public ContextAwareCallable(Callable<T> task, RequestAttributes context) {
        this.task = task;
        this.context = context;
    }

    @Override
    public T call() throws Exception {
        if (context != null) {
            RequestContextHolder.setRequestAttributes(context);
        }

        try {
            return task.call();
        } finally {
            RequestContextHolder.resetRequestAttributes();
        }
    }
}

Configuration:

@Configuration
public class ExecutorConfig extends AsyncConfigurerSupport {
    @Override
    @Bean
    public Executor getAsyncExecutor() {
        return new ContextAwarePoolExecutor();
    }
}