java - Spring Async，如何在异步任务执行器中启用请求范围

Question

我尝试在 Spring 使用@Async，在我的服务中，我使用范围为session的bean，总是出现以下错误:

org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'scopedTarget.classSession': Scope 'session' 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 session found and request already completed - cannot create new session!

如前所述，找不到 session ，请求已经完成。我实现了AsyncConfigurer以便覆盖ThreadPoolTask​​Executor:下面是我的代码

Controller :

@Autowired 
MyService myService;

@RequestMapping(value = "/doIt", method = RequestMethod.PUT)
public HttpEntity initiateCurrent(..){

myService.do();
...
}

我的服务

@Autowired 
ClassWithScopeSession classSession;

@Async("taskExecutor")
public void do(){
....
...
classSession.doService();
}

//覆盖ThreadPoolTask​​Executor

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

    @Autowired
    private ApplicationContext appContext;

    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();
        }
    }
}

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()));
    }
}

@Configuration
@EnableAsync
public class ExecutorConfig  implements AsyncConfigurer {

    @Override
    @Bean(name="taskExecutor")
    public Executor getAsyncExecutor() {
        return new ContextAwarePoolExecutor();
    }

    @Override
    public AsyncUncaughtExceptionHandler getAsyncUncaughtExceptionHandler() {
        return null;
    }
}

我遵循了这个 response

Answer 1

您需要改写execute方法:

@Override
public void execute(Runnable task) {
    super.execute(new ContextAwareCallable(task, RequestContextHolder.currentRequestAttributes()));
}

并将您的ContextAwareCallable更新为:

public class ContextAwareCallable implements Runnable {

private Runnable task;
private RequestAttributes context;

public ContextAwareCallable(Runnable task, RequestAttributes context) {
    this.task = task;
    this.context = context;
}

@Override
public void run() {
    if (context != null) {
        RequestContextHolder.setRequestAttributes(context);
    }

    task.run();
}

}

我不是专家，但是这种解决方案对我有用。

使用 @Async注释方法后，它将在 execute()类上运行 ThreadPoolTaskExecutor方法，而不是 submit()或 submitListenable()。

在我的解决方案中，它返回 CompletableFuture。这很奇怪，因为execute不会返回任何东西。

希望它能对某人有所帮助。