asynchronous - EJB 异步线程与 Vaadin，注入(inject)不工作(Vaadin 8、Vaadin-CDI、EJB ManagedExecutorService 线程)

Question

我是 Vaadin 框架和 Java EE 的新手。我正在使用 Vaadin Framework 8.1.6，Vaadin-CDI 插件 2.0.0，在 TomEE 7.0.2 服务器上运行。我正在尝试使用 EJB 托管线程池 (ManagedExecutorService) 进行异步/后台数据加载。我在使用一些注入(inject)的 bean 时遇到问题。

所有注入(inject)的 bean 在单线程 UI 中都运行良好。当我想在后台线程中使用一些注入(inject)的bean时，其中一些无法访问。

Vaadin-CDI 用户界面

@CDIUI("")
@Theme("myuitheme")
@Push
public class MyUI extends UI {

    // ...

    @WebServlet(urlPatterns = "/*", name = "MyUIServlet", asyncSupported = true)
    @VaadinServletConfiguration(ui = MyUI.class, productionMode = false)
        public static class MyUIServlet extends VaadinCDIServlet {
        }
    }

数据服务

@NormalUIScoped
public class DataService {

    // consts, functions, ...

    public Data getData(String param) {
        // call REST service, load, decode and aggregate data
        // ...
    }
}

我的 View

@CDIView(value=MyView.VIEWNAME, supportsParameters=true)
public class MyView extends Panel implements View {

    public final static String VIEWNAME = "main";

    @Resource
    private ManagedExecutorService executor;

    @Inject
    private MyUI ui;

    @Inject
    private DataService dataService;

    public void fun1() {
        System.out.println("fun1, thread_id: " + Thread.currentThread().getId());
        Future<Data> dataFuture = executor.submit(() -> loadData(param));
        // ...
    }

    private Data loadData(String param) {

        // launched in executor thread
        System.out.println("loadData, thread_id: " + Thread.currentThread().getId());

        // accessing injected ui works fine, the ui is updated correctly
        ui.access(() -> {
            clearMyView();
        }

        // accessing injected dataService doesn't work
        // exception: java.lang.IllegalStateException
        Data data = dataService.getData(param);

        ui.access(() -> {
            updateMyView(data);
        }

        return data;
    }

    //...

}

日志

fun1, thread_id: 77

loadData, thread_id: 102

异常

java.lang.IllegalStateException: Session data not recoverable for DataService, WebBeansType:MANAGED, Name:null, API Types:[xxx.DataService,java.lang.Object], Qualifiers:[javax.enterprise.inject.Default,javax.enterprise.inject.Any] at com.vaadin.cdi.internal.UIScopedContext.getContextualStorage(UIScopedContext.java:68) at org.apache.deltaspike.core.util.context.AbstractContext.get(AbstractContext.java:113) at com.vaadin.cdi.internal.AbstractVaadinContext.get(AbstractVaadinContext.java:154) at com.vaadin.cdi.internal.ContextWrapper.get(ContextWrapper.java:49) at org.apache.webbeans.intercept.NormalScopedBeanInterceptorHandler.getContextualInstance(NormalScopedBeanInterceptorHandler.java:101) at org.apache.webbeans.intercept.NormalScopedBeanInterceptorHandler.get(NormalScopedBeanInterceptorHandler.java:71) at xxx.myui.data.DataService$$OwbNormalScopeProxy0.getData(xxx/myui/data/DataService.java) at xxx.myui.view.MyView.loadData(MyView.java:855) at xxx.myui.view.MyView.lambda$27(MyView.java:645) at org.apache.openejb.threads.task.CUCallable$1.call(CUCallable.java:34) at org.apache.openejb.threads.task.CUTask.invoke(CUTask.java:100) at org.apache.openejb.threads.task.CUCallable.call(CUCallable.java:31) at java.util.concurrent.FutureTask.run(Unknown Source) at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source) at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source) at java.lang.Thread.run(Unknown Source)

怎么了？

Answer 1

您对注释 @NormalUIScoped 有什么具体原因吗？如果不是，则此更改有效

// @NormalUIScoped // why is this ?
@UIScoped @Stateful
public class DataService {
   ...
}