@Named bean中的@Asynchronous CDI事件和@Observes方法 [英] @Asynchronous CDI Events and an @Observes method in @Named bean

问题描述

我有CDI事件来通知我的JSF应用程序EJB进程的进度。当一切都同步时，代码可以正常工作。

  @Stateless 
公共类MySessionBean实现了Serializable {
 
 @注入
 @ProcessEvent 
 Event< ProcessEvent> processEvent; //也尝试使用BeanManager 
 
 @Asynchronous //此注释破坏了我的代码
 public void runLongProcess（）{
 processEvent.fire（new ProcessEvent（））; 
} 
 
} 
  

。

  @Named 
 @ViewScoped 
公共类ManagedBean实现可序列化{
 
 @EJB 
 MySessionBean sessionBean; 
 
 public void runProcess（）{
 sessionBean.runLongProcess（）; 
} 
 
 @Asynchronous //此注释无效
 public void onEvent（@Observes @ProcessEvent ProcessEvent event）{
 LOGGER.log（Level.INFO ，已收到事件）； //从未调用过
} 
} 
  

如果我使用<$ c在$code> runLongProcess（）上的$ c> @Asyncchronous 注释中，JSF @Observer 方法是

我如何实现此功能？

JSF 2.2
Glassfish 3.1
JEE 7
Java 8
Omnifaces 2.3

解决方案

在任何地方都不一定意味着HTTP请求在那个时刻和那个线程中。因此，此时并不一定有一个JSF视图可用/可识别（更不用说HTTP请求或会话了。）

它将在应用程序范围的bean中工作。 / p>

鉴于您使用的是OmniFaces 2.3，值得尝试一下 < o：socket> 即可满足您的需求。它的文档也准确地描述了这种情况，以及如何借助回调正确解决此问题（并通过Web套接字将结果推送到视图）。

  @注入
私人SomeService someService; 
 
 @ Inject @Push 
 private PushContext someChannel; 
 
 public void someAction（）{
 someService.someAsyncServiceMethod（entity，message-> someChannel.send（message））; 
} 
  

  @异步
 public void someAsyncServiceMethod（Entityentity，Consumer< Object>回调）{
 // ...（有些漫长的过程）
 callback.accept（ entity.getSomeProperty（））; 
} 
  

I have CDI Events in place to notify my JSF application of progress from EJB processes. The code works fine when everything is synchronous.

@Stateless
public class MySessionBean implements Serializable {

    @Inject
    @ProcessEvent
    Event<ProcessEvent> processEvent; // Also tried to use BeanManager

    @Asynchronous // This annotation breaks my code
    public void runLongProcess() {
        processEvent.fire(new ProcessEvent());
    }

}

.

@Named
@ViewScoped
public class ManagedBean implements Serializable {

    @EJB
    MySessionBean sessionBean;

    public void runProcess () {
        sessionBean.runLongProcess();
    }

    @Asynchronous // This annotation doesn't work
    public void onEvent(@Observes @ProcessEvent ProcessEvent event){
        LOGGER.log(Level.INFO, "Event was received"); // Never called
    }
}

If I use an @Asychronous annotation on runLongProcess(), the JSF @Observer method is never called.

How can I achieve this functionality ?

JSF 2.2 Glassfish 3.1 JEE 7 Java 8 Omnifaces 2.3

解决方案

There's not necessarily means of a HTTP request anywhere at that moment and in that thread. Therefore, there's not necessarily a JSF view available/identifiable at that moment (let alone a HTTP request or session).

It'll work in an application scoped bean.

Given that you're using OmniFaces 2.3, it might be worth the effort to take a look at <o:socket> to solve the requirement you had in mind. Its documentation also describes exactly this case and how to solve it properly with help of callbacks (and push the result via a web socket to the view).

@Inject
private SomeService someService;

@Inject @Push
private PushContext someChannel;

public void someAction() {
    someService.someAsyncServiceMethod(entity, message -> someChannel.send(message));
}

@Asynchronous
public void someAsyncServiceMethod(Entity entity, Consumer<Object> callback) {
    // ... (some long process)
    callback.accept(entity.getSomeProperty());
}

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