4

在我的 backing-bean 中，我有一组不同子类的对象共享一个公共接口。在视图内部，一个ui:repeat迭代这个集合。在这个循环中，必须根据接口的具体实现来呈现不同的属性。

我将问题减少到以下支持 bean：

@Named
@SessionScoped
public class DummyBean implements Serializable {
    private List<Type> objects = new ArrayList<Type>();

    public void add1() {
        objects.add(new Type1());
    }

    public void add2() {
        objects.add(new Type2());
    }

    public void remove(Type o) {
        objects.remove(o);
    }

    // Getter.
}

Type以及由方法add1和添加的以下实现add2。它们有一些共同的属性，但也可能有不同的属性，getType1OnlyMethod()如下例所示：

public class Type1 implements Type {
    @Override
    public String getType() { return "1"; }

    public List<String> getType1OnlyMethod() {
        return Arrays.asList("only1", "only2");
    }

    // ...
}

public class Type2 implements Type {
    @Override
    public String getType() { return "2"; }

    // ...
}

在视图中，我想遍历存储在中的所有对象DummyBean并显示它们的内容。根据对象的具体类型，仅在类中实现的方法Type1可以使用rendered-attribute 进行条件渲染调用：

<h:form id="dummyForm">
  <ui:repeat value="#{dummyBean.objects}" var="_obj" >
    <h:outputText value="Type of the Object is #{_obj.type}." />
    <h:panelGroup rendered="#{_obj.type eq '1'}">
      <ui:repeat value="#{_obj.type1OnlyMethod}" var="_oneOnlyObject" varStatus="_status" >
        <h:outputText value="#{_oneOnlyObject}" />
      </ui:repeat>
    </h:panelGroup>
    <h:commandLink value="remove" action="#{dummyBean.remove(_obj)}">
      <f:ajax render="dummyForm" />
    </h:commandLink>
    <br/>
  </ui:repeat>

  <h:commandLink value="add1" action="#{dummyBean.add1}">
    <f:ajax render="dummyForm" />
  </h:commandLink>
  <br/>
  <h:commandLink value="add2" action="#{dummyBean.add2}">
    <f:ajax render="dummyForm" />
  </h:commandLink>
</h:form>

使用h:commandLink页面上的 s 我可以随意添加和删除Type1对象。如果我添加Type2对象，它们会按预期呈现。但是当我尝试删除其中一个Type2对象时，在渲染响应阶段出现异常（尽管列表中是否有其他元素）：

2014-03-24 15:42:46,754 SEVERE [javax.enterprise.resource.webcontainer.jsf.application] (default task-11) Error Rendering View[/transition/beginTestSite.xhtml]:
   javax.el.PropertyNotFoundException: /transition/beginTestSite.xhtml @23,96 value="#{_obj.type1OnlyMethod}": The class 'at.co.xss.Type2' does not have the property 'type1OnlyMethod'.
        at com.sun.faces.facelets.el.TagValueExpression.getValue(TagValueExpression.java:111) [jsf-impl-2.2.5-jbossorg-3.jar:]
        at com.sun.faces.facelets.component.UIRepeat.getValue(UIRepeat.java:279) [jsf-impl-2.2.5-jbossorg-3.jar:]
        at com.sun.faces.facelets.component.UIRepeat.getDataModel(UIRepeat.java:255) [jsf-impl-2.2.5-jbossorg-3.jar:]
        at com.sun.faces.facelets.component.UIRepeat.setIndex(UIRepeat.java:523) [jsf-impl-2.2.5-jbossorg-3.jar:]
        at com.sun.faces.facelets.component.UIRepeat.doVisitChildren(UIRepeat.java:790) [jsf-impl-2.2.5-jbossorg-3.jar:]
        at com.sun.faces.facelets.component.UIRepeat.visitTree(UIRepeat.java:748) [jsf-impl-2.2.5-jbossorg-3.jar:]
        at javax.faces.component.UIComponent.visitTree(UIComponent.java:1700) [jboss-jsf-api_2.2_spec-2.2.5.jar:2.2.5]
        at com.sun.faces.facelets.component.UIRepeat.visitTree(UIRepeat.java:754) [jsf-impl-2.2.5-jbossorg-3.jar:]
        at javax.faces.component.UIComponent.visitTree(UIComponent.java:1700) [jboss-jsf-api_2.2_spec-2.2.5.jar:2.2.5]
        at javax.faces.component.UIForm.visitTree(UIForm.java:371) [jboss-jsf-api_2.2_spec-2.2.5.jar:2.2.5]
        at javax.faces.component.UIComponent.visitTree(UIComponent.java:1700) [jboss-jsf-api_2.2_spec-2.2.5.jar:2.2.5]
        at javax.faces.component.UIComponent.visitTree(UIComponent.java:1700) [jboss-jsf-api_2.2_spec-2.2.5.jar:2.2.5]
        at com.sun.faces.application.view.FaceletPartialStateManagementStrategy.saveView(FaceletPartialStateManagementStrategy.java:472) [jsf-impl-2.2.5-jbossorg-3.jar:]
        at com.sun.faces.application.StateManagerImpl.saveView(StateManagerImpl.java:89) [jsf-impl-2.2.5-jbossorg-3.jar:]
        at javax.faces.application.StateManager.getViewState(StateManager.java:593) [jboss-jsf-api_2.2_spec-2.2.5.jar:2.2.5]
        at com.sun.faces.context.PartialViewContextImpl.renderState(PartialViewContextImpl.java:486) [jsf-impl-2.2.5-jbossorg-3.jar:]
        at com.sun.faces.context.PartialViewContextImpl.processPartial(PartialViewContextImpl.java:328) [jsf-impl-2.2.5-jbossorg-3.jar:]
        at javax.faces.context.PartialViewContextWrapper.processPartial(PartialViewContextWrapper.java:219) [jboss-jsf-api_2.2_spec-2.2.5.jar:2.2.5]
        at org.primefaces.context.PrimePartialViewContext.processPartial(PrimePartialViewContext.java:57) [primefaces-4.0.jar:4.0]
        at org.richfaces.context.ExtendedPartialViewContextImpl.processPartial(ExtendedPartialViewContextImpl.java:218) [richfaces-core-impl-4.3.5.Final.jar:4.3.5.Final]
        at javax.faces.component.UIViewRoot.encodeChildren(UIViewRoot.java:1004) [jboss-jsf-api_2.2_spec-2.2.5.jar:2.2.5]
        at javax.faces.component.UIComponent.encodeAll(UIComponent.java:1856) [jboss-jsf-api_2.2_spec-2.2.5.jar:2.2.5]
        at com.sun.faces.application.view.FaceletViewHandlingStrategy.renderView(FaceletViewHandlingStrategy.java:435) [jsf-impl-2.2.5-jbossorg-3.jar:]
        at com.sun.faces.application.view.MultiViewHandler.renderView(MultiViewHandler.java:133) [jsf-impl-2.2.5-jbossorg-3.jar:]
        at javax.faces.application.ViewHandlerWrapper.renderView(ViewHandlerWrapper.java:337) [jboss-jsf-api_2.2_spec-2.2.5.jar:2.2.5]
        at javax.faces.application.ViewHandlerWrapper.renderView(ViewHandlerWrapper.java:337) [jboss-jsf-api_2.2_spec-2.2.5.jar:2.2.5]
        at javax.faces.application.ViewHandlerWrapper.renderView(ViewHandlerWrapper.java:337) [jboss-jsf-api_2.2_spec-2.2.5.jar:2.2.5]
        at javax.faces.application.ViewHandlerWrapper.renderView(ViewHandlerWrapper.java:337) [jboss-jsf-api_2.2_spec-2.2.5.jar:2.2.5]
        at com.sun.faces.lifecycle.RenderResponsePhase.execute(RenderResponsePhase.java:120) [jsf-impl-2.2.5-jbossorg-3.jar:]
        at com.sun.faces.lifecycle.Phase.doPhase(Phase.java:101) [jsf-impl-2.2.5-jbossorg-3.jar:]
        at com.sun.faces.lifecycle.LifecycleImpl.render(LifecycleImpl.java:219) [jsf-impl-2.2.5-jbossorg-3.jar:]
        at javax.faces.webapp.FacesServlet.service(FacesServlet.java:647) [jboss-jsf-api_2.2_spec-2.2.5.jar:2.2.5]
        at io.undertow.servlet.handlers.ServletHandler.handleRequest(ServletHandler.java:85) [undertow-servlet-1.0.0.Final.jar:1.0.0.Final]
        at io.undertow.servlet.handlers.FilterHandler$FilterChainImpl.doFilter(FilterHandler.java:130) [undertow-servlet-1.0.0.Final.jar:1.0.0.Final]
        at org.apache.shiro.web.servlet.AbstractShiroFilter.executeChain(AbstractShiroFilter.java:449) [shiro-web-1.2.2.jar:1.2.2]
        at org.apache.shiro.web.servlet.AbstractShiroFilter$1.call(AbstractShiroFilter.java:365) [shiro-web-1.2.2.jar:1.2.2]
        at org.apache.shiro.subject.support.SubjectCallable.doCall(SubjectCallable.java:90) [shiro-core-1.2.2.jar:1.2.2]
        at org.apache.shiro.subject.support.SubjectCallable.call(SubjectCallable.java:83) [shiro-core-1.2.2.jar:1.2.2]
        at org.apache.shiro.subject.support.DelegatingSubject.execute(DelegatingSubject.java:383) [shiro-core-1.2.2.jar:1.2.2]
        at org.apache.shiro.web.servlet.AbstractShiroFilter.doFilterInternal(AbstractShiroFilter.java:362) [shiro-web-1.2.2.jar:1.2.2]
        at org.apache.shiro.web.servlet.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:125) [shiro-web-1.2.2.jar:1.2.2]
        at io.undertow.servlet.core.ManagedFilter.doFilter(ManagedFilter.java:56) [undertow-servlet-1.0.0.Final.jar:1.0.0.Final]
        at io.undertow.servlet.handlers.FilterHandler$FilterChainImpl.doFilter(FilterHandler.java:132) [undertow-servlet-1.0.0.Final.jar:1.0.0.Final]
        at io.undertow.servlet.handlers.FilterHandler.handleRequest(FilterHandler.java:85) [undertow-servlet-1.0.0.Final.jar:1.0.0.Final]
        at io.undertow.servlet.handlers.security.ServletSecurityRoleHandler.handleRequest(ServletSecurityRoleHandler.java:61) [undertow-servlet-1.0.0.Final.jar:1.0.0.Final]
        at io.undertow.servlet.handlers.ServletDispatchingHandler.handleRequest(ServletDispatchingHandler.java:36) [undertow-servlet-1.0.0.Final.jar:1.0.0.Final]
        at org.wildfly.extension.undertow.security.SecurityContextAssociationHandler.handleRequest(SecurityContextAssociationHandler.java:78)
        at io.undertow.server.handlers.PredicateHandler.handleRequest(PredicateHandler.java:25) [undertow-core-1.0.0.Final.jar:1.0.0.Final]
        at io.undertow.servlet.handlers.security.SSLInformationAssociationHandler.handleRequest(SSLInformationAssociationHandler.java:113) [undertow-servlet-1.0.0.Final.jar:1.0.0.Final]
        at io.undertow.security.handlers.AuthenticationCallHandler.handleRequest(AuthenticationCallHandler.java:52) [undertow-core-1.0.0.Final.jar:1.0.0.Final]
        at io.undertow.security.handlers.AbstractConfidentialityHandler.handleRequest(AbstractConfidentialityHandler.java:45) [undertow-core-1.0.0.Final.jar:1.0.0.Final]
        at io.undertow.servlet.handlers.security.ServletConfidentialityConstraintHandler.handleRequest(ServletConfidentialityConstraintHandler.java:61) [undertow-servlet-1.0.0.Final.jar:1.0.0.Final]
        at io.undertow.servlet.handlers.security.CachedAuthenticatedSessionHandler.handleRequest(CachedAuthenticatedSessionHandler.java:70) [undertow-servlet-1.0.0.Final.jar:1.0.0.Final]
        at io.undertow.security.handlers.SecurityInitialHandler.handleRequest(SecurityInitialHandler.java:76) [undertow-core-1.0.0.Final.jar:1.0.0.Final]
        at io.undertow.server.handlers.PredicateHandler.handleRequest(PredicateHandler.java:25) [undertow-core-1.0.0.Final.jar:1.0.0.Final]
        at org.wildfly.extension.undertow.security.jacc.JACCContextIdHandler.handleRequest(JACCContextIdHandler.java:61)
        at io.undertow.server.handlers.PredicateHandler.handleRequest(PredicateHandler.java:25) [undertow-core-1.0.0.Final.jar:1.0.0.Final]
        at io.undertow.server.handlers.PredicateHandler.handleRequest(PredicateHandler.java:25) [undertow-core-1.0.0.Final.jar:1.0.0.Final]
        at io.undertow.servlet.handlers.ServletInitialHandler.handleFirstRequest(ServletInitialHandler.java:240) [undertow-servlet-1.0.0.Final.jar:1.0.0.Final]
        at io.undertow.servlet.handlers.ServletInitialHandler.dispatchRequest(ServletInitialHandler.java:227) [undertow-servlet-1.0.0.Final.jar:1.0.0.Final]
        at io.undertow.servlet.handlers.ServletInitialHandler.access$000(ServletInitialHandler.java:73) [undertow-servlet-1.0.0.Final.jar:1.0.0.Final]
        at io.undertow.servlet.handlers.ServletInitialHandler$1.handleRequest(ServletInitialHandler.java:146) [undertow-servlet-1.0.0.Final.jar:1.0.0.Final]
        at io.undertow.server.Connectors.executeRootHandler(Connectors.java:168) [undertow-core-1.0.0.Final.jar:1.0.0.Final]
        at io.undertow.server.HttpServerExchange$1.run(HttpServerExchange.java:687) [undertow-core-1.0.0.Final.jar:1.0.0.Final]
        at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145) [rt.jar:1.7.0_45]
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615) [rt.jar:1.7.0_45]
        at java.lang.Thread.run(Thread.java:744) [rt.jar:1.7.0_45]
Caused by: javax.el.PropertyNotFoundException: The class 'at.co.xss.Type2' does not have the property 'type1OnlyMethod'.
        at javax.el.BeanELResolver.getBeanProperty(BeanELResolver.java:730) [javax.el-3.0.0.jar:3.0.0]
        at javax.el.BeanELResolver.getValue(BeanELResolver.java:351) [javax.el-3.0.0.jar:3.0.0]
        at com.sun.faces.el.DemuxCompositeELResolver._getValue(DemuxCompositeELResolver.java:176) [jsf-impl-2.2.5-jbossorg-3.jar:]
        at com.sun.faces.el.DemuxCompositeELResolver.getValue(DemuxCompositeELResolver.java:203) [jsf-impl-2.2.5-jbossorg-3.jar:]
        at com.sun.el.parser.AstValue.getValue(AstValue.java:140) [javax.el-3.0.0.jar:3.0.0]
        at com.sun.el.parser.AstValue.getValue(AstValue.java:204) [javax.el-3.0.0.jar:3.0.0]
        at com.sun.el.ValueExpressionImpl.getValue(ValueExpressionImpl.java:226) [javax.el-3.0.0.jar:3.0.0]
        at org.jboss.weld.el.WeldValueExpression.getValue(WeldValueExpression.java:50) [weld-core-impl-2.1.2.Final.jar:2014-01-09 09:23]
        at org.jboss.weld.el.WeldValueExpression.getValue(WeldValueExpression.java:50) [weld-core-impl-2.1.2.Final.jar:2014-01-09 09:23]
        at com.sun.faces.facelets.el.TagValueExpression.getValue(TagValueExpression.java:109) [jsf-impl-2.2.5-jbossorg-3.jar:]
        ... 66 more

似乎在渲染响应阶段，嵌套ui:repeat是为当前删除的Type2对象“执行”的。

如果我删除第二个（嵌套）ui:repeat并添加一些纯文本h:outputText来访问仅在 中可用的属性，那么Type1当我添加或删除元素时，一切都会再次正常工作：

<h:form id="dummyForm">
  <ui:repeat value="#{dummyBean.objects}" var="_obj" >
    <!-- ... -->
    <h:panelGroup rendered="#{_obj.type eq '1'}">
      <h:outputText value="#{_obj.type1OnlyMethod.size()}" />
    </h:panelGroup>
    <!-- ... -->
</h:form>

有人对这个话题有任何想法吗？

（运行于JEE7应用服务器（Wildfly 8.0.0.Final））

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2 回答 2

3

这是由 Mojarra 的状态管理中的一个错误引起的，正如我的同事 Arjan Tijms 所报告的，该错误<ui:repeat>已根据问题 3215进行了修复。在zeef.com ( 、和)上迭代不同的Block实例时，我们也遇到了这个问题。该修复程序在Mojarra 2.2.7和 JSF 2.0/2.1 中可用，根据issue 3221向后移植到Mojarra 2.1.29。所以至少升级到那个版本（或者只是根据Mojarra 主页提供的最新版本）应该可以做到。LinkBlockImageBlockTextBlockFeedBlock

否则，您最好的选择是替换<ui:repeat>为<c:forEach>.

于 2014-08-12T18:27:39.073 回答
1

在我的情况下，我没有选择升级 Mojarra 的版本并避免 c:forEach （当与 ui 可选呈现的组件一起使用时会导致许多副作用）我将 ui:repeat 替换为 ap:dataList 并且它起作用了。您必须做一些 CSS 样式来隐藏项目符号，但我认为这是物有所值的。我希望它可以帮助某人；）

于 2016-08-19T14:13:45.117 回答