JSF InputText 到 forEach 循环中的整数数组

Question

这是我在这里的第一篇文章，所以请对我的问题提出批评，如果我问错了，请告诉我。

问题是我想在<c:forEach> 循环中创建<h:inputText>。这些字段应该获取值以存储在 bean 的属性中，该属性是 Integers 的数组。

当我在没有循环的情况下使用它时，如下所示，它工作得很好。 mac 是一个表示矩阵的 bean。 el 是一个数组，表示矩阵的九个元素。

<table>
    <tr>
        <td><h:inputText value="#{mac.el[0]}" /></td>
        <td><h:inputText value="#{mac.el[1]}" /></td>
        <td><h:inputText value="#{mac.el[2]}" /></td>
    </tr>
    <tr>
        <td><h:inputText value="#{mac.el[3]}" /></td>
        <td><h:inputText value="#{mac.el[4]}" /></td>
        <td><h:inputText value="#{mac.el[5]}" /></td>
    </tr>
    <tr>
        <td><h:inputText value="#{mac.el[6]}" /></td>
        <td><h:inputText value="#{mac.el[7]}" /></td>
        <td><h:inputText value="#{mac.el[8]}" /></td>
    </tr>
</table>

但是，当我用循环将其包裹起来时，如下所示，它没有。

<table>
<c:forEach items="#{mac.el}" varStatus="loop">
  <c:if test="${loop.index%3==0}"><tr></c:if>
  <td>
  <h:inputText value="#{mac.el[loop.index]}" />
  </td>
  <c:if test="${loop.index%3==2}"></tr></c:if>
</c:forEach>
</table>

起初，我有一个转换异常，但发现一个问题，我发现我应该使用Integer[] 而不是int[]。现在它会抛出IllegalArgumentException，但至少它可以在没有循环的情况下工作。

java.lang.IllegalArgumentException
    at javax.el.ArrayELResolver.toInteger(ArrayELResolver.java:339)
    at javax.el.ArrayELResolver.getType(ArrayELResolver.java:108)
    at com.sun.faces.el.DemuxCompositeELResolver._getType(DemuxCompositeELResolver.java:220)
    at com.sun.faces.el.DemuxCompositeELResolver.getType(DemuxCompositeELResolver.java:248)
    at com.sun.el.parser.AstValue.getType(AstValue.java:91)
    at com.sun.el.ValueExpressionImpl.getType(ValueExpressionImpl.java:201)
    at com.sun.faces.renderkit.html_basic.HtmlBasicInputRenderer.getConvertedValue(HtmlBasicInputRenderer.java:95)
    at javax.faces.component.UIInput.getConvertedValue(UIInput.java:1122)
    at javax.faces.component.UIInput.validate(UIInput.java:1030)
    at javax.faces.component.UIInput.executeValidate(UIInput.java:1334)
    at javax.faces.component.UIInput.processValidators(UIInput.java:757)
    at javax.faces.component.UIForm.processValidators(UIForm.java:269)
    at javax.faces.component.UIComponentBase.processValidators(UIComponentBase.java:1298)
    at javax.faces.component.UIViewRoot.processValidators(UIViewRoot.java:1332)
    at com.sun.faces.lifecycle.ProcessValidationsPhase.execute(ProcessValidationsPhase.java:77)
    at com.sun.faces.lifecycle.Phase.doPhase(Phase.java:100)
    at com.sun.faces.lifecycle.LifecycleImpl.execute(LifecycleImpl.java:201)
    at javax.faces.webapp.FacesServlet.service(FacesServlet.java:670)
    at org.apache.catalina.core.StandardWrapper.service(StandardWrapper.java:1540)
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:217)
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:119)
    at org.apache.catalina.core.StandardPipeline.doInvoke(StandardPipeline.java:611)
    at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:550)
    at com.sun.enterprise.web.WebPipeline.invoke(WebPipeline.java:99)
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:114)
    at org.apache.catalina.connector.CoyoteAdapter.doService(CoyoteAdapter.java:332)
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:199)
    at com.sun.enterprise.v3.services.impl.ContainerMapper$HttpHandlerCallable.call(ContainerMapper.java:463)
    at com.sun.enterprise.v3.services.impl.ContainerMapper.service(ContainerMapper.java:168)
    at org.glassfish.grizzly.http.server.HttpHandler.runService(HttpHandler.java:206)
    at org.glassfish.grizzly.http.server.HttpHandler.doHandle(HttpHandler.java:180)
    at org.glassfish.grizzly.http.server.HttpServerFilter.handleRead(HttpServerFilter.java:242)
    at org.glassfish.grizzly.filterchain.ExecutorResolver$9.execute(ExecutorResolver.java:119)
    at org.glassfish.grizzly.filterchain.DefaultFilterChain.executeFilter(DefaultFilterChain.java:284)
    at org.glassfish.grizzly.filterchain.DefaultFilterChain.executeChainPart(DefaultFilterChain.java:201)
    at org.glassfish.grizzly.filterchain.DefaultFilterChain.execute(DefaultFilterChain.java:133)
    at org.glassfish.grizzly.filterchain.DefaultFilterChain.process(DefaultFilterChain.java:112)
    at org.glassfish.grizzly.ProcessorExecutor.execute(ProcessorExecutor.java:77)
    at org.glassfish.grizzly.nio.transport.TCPNIOTransport.fireIOEvent(TCPNIOTransport.java:539)
    at org.glassfish.grizzly.strategies.AbstractIOStrategy.fireIOEvent(AbstractIOStrategy.java:112)
    at org.glassfish.grizzly.strategies.WorkerThreadIOStrategy.run0(WorkerThreadIOStrategy.java:117)
    at org.glassfish.grizzly.strategies.WorkerThreadIOStrategy.access$100(WorkerThreadIOStrategy.java:56)
    at org.glassfish.grizzly.strategies.WorkerThreadIOStrategy$WorkerThreadRunnable.run(WorkerThreadIOStrategy.java:137)
    at org.glassfish.grizzly.threadpool.AbstractThreadPool$Worker.doWork(AbstractThreadPool.java:593)
    at org.glassfish.grizzly.threadpool.AbstractThreadPool$Worker.run(AbstractThreadPool.java:573)
    at java.lang.Thread.run(Thread.java:748)

Answer 1

JSTL c:forEach 是一个标签处理程序，在视图构建期间被调用。这会导致 JSF 出现问题，因为它会在呈现响应期间呈现其组件。不要混合它们。

您可以使用ui:repeat解决您的问题。

您可以check the answer of this question 以获得更好的解释。