Question

环境：

WildFly 9.0.1 / 9.0.2
Java EE 7完整档案
焊接CDI环境。

由于我期望的请求数量，我想在FacesServlet之上实现异步请求，并且这样做了：

public class AsyncFacesServlet extends HttpServlet {

    private static final long serialVersionUID = 111966573758921845L;

    private FacesServlet delegate;

    @Inject
    private BeanManager beanManager;

    @Inject
    private ServletContext servletContext;

    @Override
    public void init(final ServletConfig servletConfig) throws ServletException {
        delegate = new FacesServlet();
        delegate.init(servletConfig);
    }

    @Override
    public void destroy() {
        delegate.destroy();
    }

    @Override
    public ServletConfig getServletConfig() {
        return delegate.getServletConfig();
    }

    @Override
    public String getServletInfo() {
        return delegate.getServletInfo();
    }

    @Override
    public void service(final ServletRequest request, final ServletResponse response) throws ServletException, IOException {
        final AsyncContext asyncContext = request.isAsyncStarted()
                ? request.getAsyncContext() : request.startAsync(request, response);
        final Runnable runnable = () -> {

            try {
                delegate.service(request, response);
            } catch (final IOException | ServletException ex) {
                throw Throwables.propagate(ex);
            }
        };

        asyncContext.start(runnable);
    }
}

然后将我的web.xml更新为：

<servlet>
    <servlet-name>Faces Servlet</servlet-name>
    <servlet-class>com.mycompany.service.faces.AsyncFacesServlet</servlet-class>
    <load-on-startup>1</load-on-startup>
    <async-supported>true</async-supported>
</servlet>

部署时，我得到以下异常，这表示Weld未在asynccontext中正确初始化。

SEVERE [javax.enterprise.resource.webcontainer.jsf.application] (default task-38) Error Rendering View[/login.xhtml]: org.jboss.weld.context.ContextNotActiveException: WELD-001303: No active contexts for scope type javax.enterprise.context.RequestScoped
    at org.jboss.weld.manager.BeanManagerImpl.getContext(BeanManagerImpl.java:708)
    at org.jboss.weld.bean.ContextualInstanceStrategy$DefaultContextualInstanceStrategy.get(ContextualInstanceStrategy.java:95)
    at org.jboss.weld.bean.ContextualInstanceStrategy$CachingContextualInstanceStrategy.get(ContextualInstanceStrategy.java:178)
    at org.jboss.weld.bean.ContextualInstance.get(ContextualInstance.java:50)
    at org.jboss.weld.manager.BeanManagerImpl.getReference(BeanManagerImpl.java:761)
    at org.jboss.weld.el.AbstractWeldELResolver.lookup(AbstractWeldELResolver.java:107)
    at org.jboss.weld.el.AbstractWeldELResolver.getValue(AbstractWeldELResolver.java:90)
    at org.jboss.as.jsf.injection.weld.ForwardingELResolver.getValue(ForwardingELResolver.java:46)
    at javax.el.CompositeELResolver.getValue(CompositeELResolver.java:188)
    at com.sun.faces.el.DemuxCompositeELResolver._getValue(DemuxCompositeELResolver.java:176)
    at com.sun.faces.el.DemuxCompositeELResolver.getValue(DemuxCompositeELResolver.java:203)
    at com.sun.el.parser.AstIdentifier.getValue(AstIdentifier.java:116)
    at com.sun.el.parser.AstValue.getBase(AstValue.java:151)
    at com.sun.el.parser.AstValue.getValue(AstValue.java:200)
    at com.sun.el.ValueExpressionImpl.getValue(ValueExpressionImpl.java:226)
    at org.jboss.weld.el.WeldValueExpression.getValue(WeldValueExpression.java:50)
    at org.jboss.weld.el.WeldValueExpression.getValue(WeldValueExpression.java:50)
    at com.sun.faces.facelets.el.TagValueExpression.getValue(TagValueExpression.java:109)
    at javax.faces.component.ComponentStateHelper.eval(ComponentStateHelper.java:194)
    at javax.faces.component.ComponentStateHelper.eval(ComponentStateHelper.java:182)
    at javax.faces.component.UIOutput.getValue(UIOutput.java:174)
    at javax.faces.component.UIInput.getValue(UIInput.java:291)
    at com.sun.faces.renderkit.html_basic.HtmlBasicInputRenderer.getValue(HtmlBasicInputRenderer.java:205)
    at com.sun.faces.renderkit.html_basic.HtmlBasicRenderer.getCurrentValue(HtmlBasicRenderer.java:355)
    at com.sun.faces.renderkit.html_basic.HtmlBasicRenderer.encodeEnd(HtmlBasicRenderer.java:164)
    at javax.faces.component.UIComponentBase.encodeEnd(UIComponentBase.java:920)
    at javax.faces.component.UIComponent.encodeAll(UIComponent.java:1863)
    at javax.faces.render.Renderer.encodeChildren(Renderer.java:176)
    at javax.faces.component.UIComponentBase.encodeChildren(UIComponentBase.java:890)
    at javax.faces.component.UIComponent.encodeAll(UIComponent.java:1856)
    at javax.faces.component.UIComponent.encodeAll(UIComponent.java:1859)
    at javax.faces.component.UIComponent.encodeAll(UIComponent.java:1859)
    at com.sun.faces.application.view.FaceletViewHandlingStrategy.renderView(FaceletViewHandlingStrategy.java:458)
    at com.sun.faces.application.view.MultiViewHandler.renderView(MultiViewHandler.java:134)
    at javax.faces.application.ViewHandlerWrapper.renderView(ViewHandlerWrapper.java:337)
    at javax.faces.application.ViewHandlerWrapper.renderView(ViewHandlerWrapper.java:337)
    at javax.faces.application.ViewHandlerWrapper.renderView(ViewHandlerWrapper.java:337)
    at com.sun.faces.lifecycle.RenderResponsePhase.execute(RenderResponsePhase.java:120)
    at com.sun.faces.lifecycle.Phase.doPhase(Phase.java:101)
    at com.sun.faces.lifecycle.LifecycleImpl.render(LifecycleImpl.java:219)
    at javax.faces.webapp.FacesServlet.service(FacesServlet.java:659)
    at com.mycompany.service.faces.servlet.AsyncFacesServlet.lambda$service$17(AsyncFacesServlet.java:61)

发生的事情是，Weld未正确初始化或上下文未传播到异步上下文执行。

如何在异步请求调用时传播或重新创建焊接上下文？

Answer 1

我将在答案前加上一个说明，即存在一个开放的CDI规范问题，以使异步行为更具可移植性，Specify that web scoped (request, session, application) beans are injectable in async servlets

以Weld特定的方式，您可以做的是启动上下文。 Apache DeltaSpike还有一些实用程序可以使这个容器不具体，http://deltaspike.apache.org/documentation/container-control.html#ContextControlUsage

如果runnable是托管bean，则可以在焊接中使用BoundRequestContext来启动该线程的请求上下文。 More here。缺点是它是一个新的背景，而不是桥接的背景。

在异步servlet中焊接ContextNotActiveException

1 个答案: