Question

我试图将简单的JSF2.2原型从 Mojarra 2.2.5（......哪里工作正常......）迁移到 MyFaces 2.2.3但是a发生 NullPointerException 我通常使用Mojarra做的是在容器中包含（注入）以编程方式 JSF页面。

示例包含页面（ inclusion.xhtml ）是：

<h:panelGroup id="container">
</h:panelGroup>
<h:form>
    <h:commandButton value="Include page" action="#{inclusion.include('included.xhtml')}" />
</h:form>

附带页面（ included.xhtml ）包含以下内容：

    <h:outputText value="INCLUDED TEXT ..." />

这是托管bean ：

    @ManagedBean(name="inclusion")
    @RequestScoped
    public final class Inclusion {

    public void include(String contentUrl) throws IOException{
        FacesContext fc = FacesContext.getCurrentInstance();        
        FaceletContext f2ctx = (FaceletContext) fc.getAttributes().get(FaceletContext.FACELET_CONTEXT_KEY);
        UIComponent uic = fc.getViewRoot().findComponent("container");
        if (uic != null && f2ctx != null) {
            f2ctx.includeFacelet(uic, contentUrl);              
        }
    }

这是例外：

javax.el.ELException：java.lang.NullPointerException

viewId = / inclusion.xhtml   位置= /选择/ jbdevstudio7 /工作区/ .metadata / .plugins / org.eclipse.wst.server.core / TMP0 / wtpwebapps / jsf2test / inclusion.xhtml   phaseId = INVOKE_APPLICATION（5）

引起：java.lang.NullPointerException -   java.lang.NullPointerException at   org.apache.myfaces.view.facelets.impl.FaceletCompositionContextImpl.generateUniqueId（FaceletCompositionContextImpl.java:1045）

/inclusion.xhtml在第15行和第91列   行动=＆＃34;＃{inclusion.include（＆＃39; included.xhtml＆＃39;）}＆＃34; - 状态大小：0字节

这是堆栈跟踪：

org.apache.myfaces.view.facelets.el.ContextAwareELException： javax.el.ELException：java.lang.NullPointerException at org.apache.myfaces.view.facelets.el.ContextAwareTagMethodExpression.invoke（ContextAwareTagMethodExpression.java:108）在 org.apache.myfaces.application.ActionListenerImpl.processAction（ActionListenerImpl.java:74）在 org.primefaces.application.DialogActionListener.processAction（DialogActionListener.java:45）在javax.faces.component.UICommand.broadcast（UICommand.java:120）at javax.faces.component.UIViewRoot._broadcastAll（UIViewRoot.java:1172）在 javax.faces.component.UIViewRoot.broadcastEvents（UIViewRoot.java:365）在javax.faces.component.UIViewRoot._process（UIViewRoot.java:1656）在 javax.faces.component.UIViewRoot.processApplication（UIViewRoot.java:862）在 org.apache.myfaces.lifecycle.InvokeApplicationExecutor.execute（InvokeApplicationExecutor.java:42）在 org.apache.myfaces.lifecycle.LifecycleImpl.executePhase（LifecycleImpl.java:196）在 org.apache.myfaces.lifecycle.LifecycleImpl.execute（LifecycleImpl.java:143）在javax.faces.webapp.FacesServlet.service（FacesServlet.java:198）at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter（ApplicationFilterChain.java:305）在 org.apache.catalina.core.ApplicationFilterChain.doFilter（ApplicationFilterChain.java:210）在com.ocpsoft.pretty.PrettyFilter.doFilter（PrettyFilter.java:145）在 org.apache.catalina.core.ApplicationFilterChain.internalDoFilter（ApplicationFilterChain.java:243）在 org.apache.catalina.core.ApplicationFilterChain.doFilter（ApplicationFilterChain.java:210）在jplus.web.filters.FlowFilter.doFilter（FlowFilter.java:215）at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter（ApplicationFilterChain.java:243）在 org.apache.catalina.core.ApplicationFilterChain.doFilter（ApplicationFilterChain.java:210）在 org.apache.catalina.core.StandardWrapperValve.invoke（StandardWrapperValve.java:222）在 org.apache.catalina.core.StandardContextValve.invoke（StandardContextValve.java:123）在 org.apache.catalina.authenticator.AuthenticatorBase.invoke（AuthenticatorBase.java:502）在 org.apache.catalina.core.StandardHostValve.invoke（StandardHostValve.java:171）在 org.apache.catalina.valves.ErrorReportValve.invoke（ErrorReportValve.java:99）在 org.apache.catalina.valves.AccessLogValve.invoke（AccessLogValve.java:953）在 org.apache.catalina.core.StandardEngineValve.invoke（StandardEngineValve.java:118）在 org.apache.catalina.connector.CoyoteAdapter.service（CoyoteAdapter.java:408）在 org.apache.coyote.http11.AbstractHttp11Processor.process（AbstractHttp11Processor.java:1023）在 org.apache.coyote.AbstractProtocol $ AbstractConnectionHandler.process（AbstractProtocol.java:589）在 org.apache.tomcat.util.net.JIoEndpoint $ SocketProcessor.run（JIoEndpoint.java:312）在 java.util.concurrent.ThreadPoolExecutor中的$ Worker.runTask（ThreadPoolExecutor.java:886）在 java.util.concurrent.ThreadPoolExecutor中的$ Worker.run（ThreadPoolExecutor.java:908）在java.lang.Thread.run（Thread.java:662）引起： javax.el.ELException：java.lang.NullPointerException at org.apache.el.parser.AstValue.invoke（AstValue.java:291）at at org.apache.el.MethodExpressionImpl.invoke（MethodExpressionImpl.java:274）在 org.apache.myfaces.view.facelets.el.ContextAwareTagMethodExpression.invoke（ContextAwareTagMethodExpression.java:96） ... 33更多引起：java.lang.NullPointerException at org.apache.myfaces.view.facelets.impl.FaceletCompositionContextImpl.generateUniqueId（FaceletCompositionContextImpl.java:1045）在 org.apache.myfaces.view.facelets.impl.DefaultFaceletContext.generateUniqueId（DefaultFaceletContext.java:322）在 org.apache.myfaces.view.facelets.compiler.UIInstructionHandler.apply（UIInstructionHandler.java:87）在 javax.faces.view.facelets.CompositeFaceletHandler.apply（CompositeFaceletHandler.java:46）在 org.apache.myfaces.view.facelets.compiler.NamespaceHandler.apply（NamespaceHandler.java:59）在 org.apache.myfaces.view.facelets.compiler.EncodingHandler.apply（EncodingHandler.java:48）在 org.apache.myfaces.view.facelets.impl.DefaultFacelet.include（DefaultFacelet.java:514）在 org.apache.myfaces.view.facelets.impl.DefaultFacelet.include（DefaultFacelet.java:568）在 org.apache.myfaces.view.facelets.impl.DefaultFacelet.include（DefaultFacelet.java:546）在 org.apache.myfaces.view.facelets.impl.DefaultFaceletContext.includeFacelet（DefaultFaceletContext.java:240）在Inclusion.include（Inclusion.java:27）at sun.reflect.NativeMethodAccessorImpl.invoke0（Native Method）at sun.reflect.NativeMethodAccessorImpl.invoke（NativeMethodAccessorImpl.java:39）在 sun.reflect.DelegatingMethodAccessorImpl.invoke（DelegatingMethodAccessorImpl.java:25）在java.lang.reflect.Method.invoke（Method.java:597）at org.apache.el.parser.AstValue.invoke（AstValue.java:278）... 35更多

你怎么看？有没有错误？
感谢。

Answer 1

这不是一个错误。使用FaceletContext是错误的方法，因为以后它会导致重复的id和状态管理问题，因为从一开始代码就错了。相反，尝试使用这种方式：

        ViewDeclarationLanguage vdl = facesContext.getApplication().
            getViewHandler().getViewDeclarationLanguage(
                facesContext, facesContext.getViewRoot().getViewId());

        Map<String, Object> attributes = new HashMap<String, Object>();
        attributes.put("src", "/addSimpleIncludeVDL_1_1.xhtml");
        UIComponent component = vdl.createComponent(facesContext, 
            "http://java.sun.com/jsf/facelets", 
            "include", attributes);
        getChildren().add(component);

在JSF 2.2中添加了

vdl.createComponent（...），在MyFaces中，它被改进以允许这种用法。您甚至可以通过这种方式以编程方式添加复合组件。在MyFaces用户列表中，据报道这种方式非常有效。

MyFaces facelet包含中的NullPointerException

1 个答案: