CDI多线程 [英] CDI multithreading

问题描述

我们想优化我们的应用程序.正在进行一些线性的工作，可以在具有较小工作集的多个线程中执行.

We want to optimize our application. There is some streight linear work going on, that can be executed in multiple threads with smaller working sets.

从CDI管理的bean中使用@Inject批注访问我们的典型服务.同样，这样的服务也可以注入自己的依赖项，即:

Our typical service is accessed using the @Inject annotation from within our CDI-managed beans. Also such a service could have it's own dependencies injected, i.e.:

public class MyService {

   @Inject
   private OtherService otherService;

   @Inject
   private DataService1 dataService1;

   ...

   public void doSomething() {
     ...
   }
}

因为我不能在实现Runnable的类中使用@Inject. (它不是容器管理的.)我尝试在启动线程之前将所需的服务传递给类.因此，使用类似这样的方法，可使服务实例(myService)在线程内可用:

Because I can not use @Inject inside the class implementing Runnable. (It's not container managed.) I tried to pass the required services to the class before starting the thread. So, using something like this, makes the service instance (myService) available within the thread:

Class Thread1 implements Runnable{
   private MyService myService

   public Thread1(MyService myService){
      this.myService = myService;
   }

   public void run(){
      myService.doSomething();
   } 
}

在调用层次结构之后，可以调用doStometing()，因为已经传递了对myService的引用.据我了解的CDI，注入是在第一次访问属性时完成的，这意味着，当doStomething()方法尝试访问otherService或dataService1时，将执行注入.

Following the call-hierarchy the call to doStometing() is fine, because a reference to myService has been passed. As far as I understand CDI, the injection is done the moment the attribute is accessed for the first time, meaning, when the doStomething() method tries to access either otherService or dataService1, the injection would be performed.

但是到那时我收到一个例外，那就是没有可用的上下文.

At that point however I receive an exception, that there is no context available.

我还尝试使用JBossThreadExecuter类而不是 Plain-Threads -这会导致完全相同的结果.

I also tried to use the JBossThreadExecuter class instead of Plain-Threads - it leads to the very same result.

问题是，是否存在将上下文(或请求)与创建的Thread相关联的好方法?

So the question would be, if there is a nice way to associate a context (or request) with a created Thread?

对于EJB-Beans，我读到用@Asynchronous标记方法将导致该方法在托管线程中运行，该线程本身将连接到上下文.那基本上就是我要寻找的.

For EJB-Beans, I read that marking a method with @Asynchronous will cause the method to be run in a managed thread which itself will be wired to the context. That would basically be exactly what I'm searching for.

有没有办法在CDI中做到这一点?

Is there a way to do this in CDI?

或者有没有办法从非托管线程中获取context?

Or is there any way to obtain a context from within a unmanaged thread?

推荐答案

Weld允许程序化上下文管理，

Weld allows programmatic context management, (there's an example in the official docs).

但是在您采用这种方式之前，请给EJB一个机会)
@Async调用功能完全适合您的情况.作为奖励，您将获得超时拦截和事务管理.

But before you go this way give EJBs a chance )
@Async invocation functionality is there exactly for your case. And as a bonus you'll get timeout interception and transaction management.

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