ajax - 在 JSF 中呈现视图时用作标识符的内容

Question

我有一个 JSF 页面，其中有一个 ajax 调用和一个按钮提交。Ajax 调用用于在页面的一部分中提交信息，该部分包含在<h:panelGroup>.

<h:form prependId="false" id="form">
    <h:outputText value="#{msg['home.name']}" />
    <h:inputText value="#{bean.name}" id="name" />



    <h:panelGroup id="newPanel">
        <p><h:outputText value="#{msg['home.comments']}" /></p>
            <h:inputTextarea cols="30" id="comments" rows="4"
                                                     value="#{bean.comments}" >
                    <f:validateLength maximum="1000" /></h:inputTextarea>

                <h:commandLink value="#{msg['home.sendcomment']}">
                        <p:ajax listener="#{controller.saveComments()}"
                            process="#{bean.comments}" update="form:newPanel"></p:ajax>

                </h:commandLink>
    </h:panelGroup>

    <h:commandLink value="#{msg['home.submit']}" action="#{controller.submit()}"/>

</h:form>

一切正常，但我只是在测试所有场景。就在那时我发现当我在textarea中输入一些数据（例如：'aa'）并单击提交按钮时，它会显示以下错误。

18:28:47,556 SEVERE [javax.enterprise.resource.webcontainer.jsf.application] (http-localhost-127.0.0.1-8080-6) Error Rendering View[/Sample.xhtml]: javax.faces.FacesException: Cannot find component with identifier "aa" referenced from "j_idt159".
    at org.primefaces.util.ComponentUtils.findClientIds(ComponentUtils.java:250) [primefaces-3.5.jar:]
    at org.primefaces.util.AjaxRequestBuilder.addIds(AjaxRequestBuilder.java:102) [primefaces-3.5.jar:]
    at org.primefaces.util.AjaxRequestBuilder.process(AjaxRequestBuilder.java:84) [primefaces-3.5.jar:]
    at org.primefaces.component.behavior.ajax.AjaxBehaviorRenderer.getScript(AjaxBehaviorRenderer.java:63) [primefaces-3.5.jar:]
    at javax.faces.component.behavior.ClientBehaviorBase.getScript(ClientBehaviorBase.java:103) [jboss-jsf-api_2.1_spec-2.0.1.Final.jar:2.0.1.Final]
    at com.sun.faces.renderkit.RenderKitUtils.getSingleBehaviorHandler(RenderKitUtils.java:1607) [jsf-impl-2.1.7-jbossorg-2.jar:]
    at com.sun.faces.renderkit.RenderKitUtils.renderHandler(RenderKitUtils.java:1700) [jsf-impl-2.1.7-jbossorg-2.jar:]
    at com.sun.faces.renderkit.RenderKitUtils.renderOnclick(RenderKitUtils.java:451) [jsf-impl-2.1.7-jbossorg-2.jar:]
    at com.sun.faces.renderkit.html_basic.CommandLinkRenderer.renderAsActive(CommandLinkRenderer.java:231) [jsf-impl-2.1.7-jbossorg-2.jar:]
    at com.sun.faces.renderkit.html_basic.CommandLinkRenderer.encodeBegin(CommandLinkRenderer.java:125) [jsf-impl-2.1.7-jbossorg-2.jar:]
    at javax.faces.component.UIComponentBase.encodeBegin(UIComponentBase.java:820) [jboss-jsf-api_2.1_spec-2.0.1.Final.jar:2.0.1.Final]
    at com.sun.faces.renderkit.html_basic.HtmlBasicRenderer.encodeRecursive(HtmlBasicRenderer.java:302) [jsf-impl-2.1.7-jbossorg-2.jar:]
    at com.sun.faces.renderkit.html_basic.GroupRenderer.encodeChildren(GroupRenderer.java:105) [jsf-impl-2.1.7-jbossorg-2.jar:]
    at javax.faces.component.UIComponentBase.encodeChildren(UIComponentBase.java:845) [jboss-jsf-api_2.1_spec-2.0.1.Final.jar:2.0.1.Final]
    at javax.faces.component.UIComponent.encodeAll(UIComponent.java:1779) [jboss-jsf-api_2.1_spec-2.0.1.Final.jar:2.0.1.Final]
    at javax.faces.render.Renderer.encodeChildren(Renderer.java:168) [jboss-jsf-api_2.1_spec-2.0.1.Final.jar:2.0.1.Final]
    at javax.faces.component.UIComponentBase.encodeChildren(UIComponentBase.java:845) [jboss-jsf-api_2.1_spec-2.0.1.Final.jar:2.0.1.Final]
    at javax.faces.component.UIComponent.encodeAll(UIComponent.java:1779) [jboss-jsf-api_2.1_spec-2.0.1.Final.jar:2.0.1.Final]
    at javax.faces.component.UIComponent.encodeAll(UIComponent.java:1782) [jboss-jsf-api_2.1_spec-2.0.1.Final.jar:2.0.1.Final]
    at javax.faces.component.UIComponent.encodeAll(UIComponent.java:1782) [jboss-jsf-api_2.1_spec-2.0.1.Final.jar:2.0.1.Final]
    at com.sun.faces.application.view.FaceletViewHandlingStrategy.renderView(FaceletViewHandlingStrategy.java:402) [jsf-impl-2.1.7-jbossorg-2.jar:]
    at com.sun.faces.application.view.MultiViewHandler.renderView(MultiViewHandler.java:125) [jsf-impl-2.1.7-jbossorg-2.jar:]
    at javax.faces.application.ViewHandlerWrapper.renderView(ViewHandlerWrapper.java:288) [jboss-jsf-api_2.1_spec-2.0.1.Final.jar:2.0.1.Final]
    at javax.faces.application.ViewHandlerWrapper.renderView(ViewHandlerWrapper.java:288) [jboss-jsf-api_2.1_spec-2.0.1.Final.jar:2.0.1.Final]
    at org.apache.myfaces.tomahawk.application.ResourceViewHandlerWrapper.renderView(ResourceViewHandlerWrapper.java:93) [tomahawk20-1.1.11.jar:1.1.11]
    at com.sun.faces.lifecycle.RenderResponsePhase.execute(RenderResponsePhase.java:121) [jsf-impl-2.1.7-jbossorg-2.jar:]
    at com.sun.faces.lifecycle.Phase.doPhase(Phase.java:101) [jsf-impl-2.1.7-jbossorg-2.jar:]
    at com.sun.faces.lifecycle.LifecycleImpl.render(LifecycleImpl.java:139) [jsf-impl-2.1.7-jbossorg-2.jar:]
    at javax.faces.webapp.FacesServlet.service(FacesServlet.java:594) [jboss-jsf-api_2.1_spec-2.0.1.Final.jar:2.0.1.Final]
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:329) [jbossweb-7.0.13.Final.jar:]
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:248) [jbossweb-7.0.13.Final.jar:]
    at org.jboss.weld.servlet.ConversationPropagationFilter.doFilter(ConversationPropagationFilter.java:62) [weld-core-1.1.5.AS71.Final.jar:2012-02-10 15:31]
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:280) [jbossweb-7.0.13.Final.jar:]
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:248) [jbossweb-7.0.13.Final.jar:]
    at org.ocpsoft.rewrite.servlet.RewriteFilter.doFilter(RewriteFilter.java:191) [rewrite-servlet-2.0.2.Final.jar:2.0.2.Final]
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:280) [jbossweb-7.0.13.Final.jar:]
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:248) [jbossweb-7.0.13.Final.jar:]
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:280) [jbossweb-7.0.13.Final.jar:]
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:248) [jbossweb-7.0.13.Final.jar:]
    at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:330) [spring-security-web-3.1.4.RELEASE.jar:3.1.4.RELEASE]
    at org.springframework.security.web.access.intercept.FilterSecurityInterceptor.invoke(FilterSecurityInterceptor.java:118) [spring-security-web-3.1.4.RELEASE.jar:3.1.4.RELEASE]
    at org.springframework.security.web.access.intercept.FilterSecurityInterceptor.doFilter(FilterSecurityInterceptor.java:84) [spring-security-web-3.1.4.RELEASE.jar:3.1.4.RELEASE]
    at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:342) [spring-security-web-3.1.4.RELEASE.jar:3.1.4.RELEASE]
    at org.springframework.security.web.access.ExceptionTranslationFilter.doFilter(ExceptionTranslationFilter.java:113) [spring-security-web-3.1.4.RELEASE.jar:3.1.4.RELEASE]
    at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:342) [spring-security-web-3.1.4.RELEASE.jar:3.1.4.RELEASE]
    at org.springframework.security.web.session.SessionManagementFilter.doFilter(SessionManagementFilter.java:103) [spring-security-web-3.1.4.RELEASE.jar:3.1.4.RELEASE]
    at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:342) [spring-security-web-3.1.4.RELEASE.jar:3.1.4.RELEASE]
    at org.springframework.security.web.authentication.AnonymousAuthenticationFilter.doFilter(AnonymousAuthenticationFilter.java:113) [spring-security-web-3.1.4.RELEASE.jar:3.1.4.RELEASE]
    at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:342) [spring-security-web-3.1.4.RELEASE.jar:3.1.4.RELEASE]
    at org.springframework.security.web.servletapi.SecurityContextHolderAwareRequestFilter.doFilter(SecurityContextHolderAwareRequestFilter.java:54) [spring-security-web-3.1.4.RELEASE.jar:3.1.4.RELEASE]
    at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:342) [spring-security-web-3.1.4.RELEASE.jar:3.1.4.RELEASE]
    at org.springframework.security.web.savedrequest.RequestCacheAwareFilter.doFilter(RequestCacheAwareFilter.java:45) [spring-security-web-3.1.4.RELEASE.jar:3.1.4.RELEASE]
    at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:342) [spring-security-web-3.1.4.RELEASE.jar:3.1.4.RELEASE]
    at org.springframework.security.web.authentication.www.BasicAuthenticationFilter.doFilter(BasicAuthenticationFilter.java:150) [spring-security-web-3.1.4.RELEASE.jar:3.1.4.RELEASE]
    at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:342) [spring-security-web-3.1.4.RELEASE.jar:3.1.4.RELEASE]
    at org.springframework.security.web.authentication.AbstractAuthenticationProcessingFilter.doFilter(AbstractAuthenticationProcessingFilter.java:183) [spring-security-web-3.1.4.RELEASE.jar:3.1.4.RELEASE]
    at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:342) [spring-security-web-3.1.4.RELEASE.jar:3.1.4.RELEASE]
    at org.springframework.security.web.authentication.logout.LogoutFilter.doFilter(LogoutFilter.java:105) [spring-security-web-3.1.4.RELEASE.jar:3.1.4.RELEASE]
    at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:342) [spring-security-web-3.1.4.RELEASE.jar:3.1.4.RELEASE]
    at org.springframework.security.web.context.SecurityContextPersistenceFilter.doFilter(SecurityContextPersistenceFilter.java:87) [spring-security-web-3.1.4.RELEASE.jar:3.1.4.RELEASE]
    at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:342) [spring-security-web-3.1.4.RELEASE.jar:3.1.4.RELEASE]
    at org.springframework.security.web.FilterChainProxy.doFilterInternal(FilterChainProxy.java:192) [spring-security-web-3.1.4.RELEASE.jar:3.1.4.RELEASE]
    at org.springframework.security.web.FilterChainProxy.doFilter(FilterChainProxy.java:160) [spring-security-web-3.1.4.RELEASE.jar:3.1.4.RELEASE]
    at org.springframework.web.filter.DelegatingFilterProxy.invokeDelegate(DelegatingFilterProxy.java:346) [spring-web-3.1.4.RELEASE.jar:3.1.4.RELEASE]
    at org.springframework.web.filter.DelegatingFilterProxy.doFilter(DelegatingFilterProxy.java:259) [spring-web-3.1.4.RELEASE.jar:3.1.4.RELEASE]
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:280) [jbossweb-7.0.13.Final.jar:]
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:248) [jbossweb-7.0.13.Final.jar:]
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:275) [jbossweb-7.0.13.Final.jar:]
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:161) [jbossweb-7.0.13.Final.jar:]
    at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:397) [jbossweb-7.0.13.Final.jar:]
    at org.jboss.as.jpa.interceptor.WebNonTxEmCloserValve.invoke(WebNonTxEmCloserValve.java:50) [jboss-as-jpa-7.1.1.Final.jar:7.1.1.Final]
    at org.jboss.as.web.security.SecurityContextAssociationValve.invoke(SecurityContextAssociationValve.java:153) [jboss-as-web-7.1.1.Final.jar:7.1.1.Final]
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:155) [jbossweb-7.0.13.Final.jar:]
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102) [jbossweb-7.0.13.Final.jar:]
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109) [jbossweb-7.0.13.Final.jar:]
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:368) [jbossweb-7.0.13.Final.jar:]
    at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:877) [jbossweb-7.0.13.Final.jar:]
    at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:671) [jbossweb-7.0.13.Final.jar:]
    at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:930) [jbossweb-7.0.13.Final.jar:]
    at java.lang.Thread.run(Unknown Source) [rt.jar:1.6.0_43]

但是，如果我通过 'Send Comment' 进行操作，一切正常<h:commandLink>。
我错过了什么吗？

Answer 1

First of all, get rid of prependId="false" in <h:form> and stop using it. It's a leftover from JSF 1.x and you should never use it in JSF 2.x. With this attribute set on the parent <h:form>, the ajax functionality fails to find the components specified in <f:ajax> or <p:ajax> this way.

Second, your concrete problem is caused because you specified the literal input text as process attribute:

<h:inputTextarea id="comments" value="#{bean.comments}" />
...
<p:ajax process="#{bean.comments}" ... />

This isn't making any sense. The process attribute must represent the client ID(s) of the components to process. The submitted value is otherwise interpreted as client IDs which doesn't necessarily exist in JSF component tree. Fix it accordingly:

<h:inputTextarea id="comments" value="#{bean.comments}" />
...
<p:ajax process="comments" ... />

See also:

• How to find out client ID of component for ajax update/render? Cannot find component with expression "foo" referenced from "bar"