Question

我在尝试将托管bean作为param传递给facelet模板时遇到了很多麻烦。我试图在facelet模板上创建一个变量并通过ui：param传递它的值，但是我经常使用＆＃34;目标无法访问，标识符＆＃39; bean＆＃39;决定为null＆＃34;错误。我已经尝试将它设置为：

<p:commandButton value="Save" actionListener="#{sessionScope[bean].save}" />

它再次无效。

有人可以帮我吗？

以下是代码：

crud_template.xhtml

<ui:define name="content">

    <h:form>
        <ui:insert name="create_form">
            <!-- Default -->
        </ui:insert>

        <br />
        <br />
        <p:separator />
        <p:commandButton value="Save" actionListener="#{bean.save}" />
        <p:commandButton value="Cancel" actionListener="#{bean.cancel}" />
    </h:form>

</ui:define>

familyPersist.xhtml

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml"
    xmlns:ui="http://java.sun.com/jsf/facelets"
    xmlns:f="http://java.sun.com/jsf/core"
    xmlns:h="http://java.sun.com/jsf/html"
    xmlns:p="http://primefaces.org/ui">

<ui:composition template="/WEB-INF/templates/crud_template.xhtml">

    <ui:param name="bean" value="#{familyBean}" />

    <ui:define name="create_form">
        <h:panelGrid columns="3">
            <h:outputLabel value="Name*:" for="itemName" />
            <p:inputText id="itemName" required="true"
                value="#{familyBean.item.nmFamily}" />
        </h:panelGrid>
    </ui:define>

</ui:composition>
</html>

CrudBean.java

public abstract class CrudBean<T> {

    protected T item;

    private String redirect() {
        return "/pages/protected/" + getEntityName() + "List.jsf";
    }

    public String save() {
        return redirect();
    }

    public String cancel() {
        return redirect();
    }

    public abstract String getEntityName();

    /**
     * @return the item
     */
    public T getItem() {
        return item;
    }

    /**
     * @param item the item to set
     */
    public void setItem(T item) {
        this.item = item;
    }

}

FamilyBean.java

@Model
public class FamilyBean extends CrudBean<Family> {

    public FamilyBean() {
        item = new Family();
    }

    @Override
    public String getEntityName() {
        return "Family";
    }

}

最后，错误：

22:11:50,178 GRAVE [javax.faces.event] (http-localhost-127.0.0.1-8080-4) javax.el.PropertyNotFoundException: Target Unreachable, identifier 'bean' resolved to null
    at org.apache.el.parser.AstValue.getTarget(AstValue.java:98)
    at org.apache.el.parser.AstValue.invoke(AstValue.java:244)
    at org.apache.el.MethodExpressionImpl.invoke(MethodExpressionImpl.java:278)
    at org.jboss.weld.util.el.ForwardingMethodExpression.invoke(ForwardingMethodExpression.java:39)
    at org.jboss.weld.el.WeldMethodExpression.invoke(WeldMethodExpression.java:50)
    at javax.faces.event.MethodExpressionActionListener.processAction(MethodExpressionActionListener.java:153)
    at javax.faces.event.ActionEvent.processListener(ActionEvent.java:88)
    at javax.faces.component.UIComponentBase.broadcast(UIComponentBase.java:769)
    at javax.faces.component.UICommand.broadcast(UICommand.java:300)
    at javax.faces.component.UIViewRoot.broadcastEvents(UIViewRoot.java:794)
    at javax.faces.component.UIViewRoot.processApplication(UIViewRoot.java:1259)
    at com.sun.faces.lifecycle.InvokeApplicationPhase.execute(InvokeApplicationPhase.java:81)
    at com.sun.faces.lifecycle.Phase.doPhase(Phase.java:101)
    at com.sun.faces.lifecycle.LifecycleImpl.execute(LifecycleImpl.java:118)
    at javax.faces.webapp.FacesServlet.service(FacesServlet.java:593)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:329)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:248)
    at org.jboss.weld.servlet.ConversationPropagationFilter.doFilter(ConversationPropagationFilter.java:62)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:280)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:248)
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:275)
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:161)
    at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:489)
    at org.jboss.as.jpa.interceptor.WebNonTxEmCloserValve.invoke(WebNonTxEmCloserValve.java:50)
    at org.jboss.as.web.security.SecurityContextAssociationValve.invoke(SecurityContextAssociationValve.java:153)
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:155)
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102)
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:368)
    at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:877)
    at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:671)
    at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:930)
    at java.lang.Thread.run(Thread.java:662)

修改

我使用这个maven命令创建我的项目：

mvn archetype:generate \
    -DarchetypeArtifactId=jboss-javaee6-webapp-archetype \
    -DarchetypeGroupId=org.jboss.spec.archetypes \
    -DarchetypeVersion=7.1.1.CR2

Answer 1

我尝试了以上所有建议，但没有运气。最终对我有用的唯一事情是使用括号＆＃39;（）＆＃39;在调用方法时。我想，未找到属性异常应该是一个线索，它将属性与方法混淆。我认为这是facelets的一个错误，因为它与传统的JSF actionListener和动作方法调用不一致。

上面的例子应该适用于：

<p:commandButton value="Save" actionListener="#{bean.save()}" />

，其中

<ui:param name="bean" value="#{familyBean}" />

Answer 2

我从文档中读到的内容，@ Model与RequestScoped的@ManagedBean相同。

因此，如果我尝试修复相同的内容，我可以执行以下操作：

<强> UI：PARAM

<ui:param name="bean" value="familyBean" />

在 crud_template.xhtml ：

<p:commandButton value="Save" actionListener="#{requestscope[bean].save}" />

试试这个，这应该有效。

修改

我确实试图复制它，并且能够解决它。

我在这里发布示例代码供您参考。

也想分享一件事：如果bean没有在xhtml中注入一次，你将无法从中获取引用。

Template page: <ui:composition xmlns="http://www.w3.org/1999/xhtml" xmlns:h="http://java.sun.com/jsf/html" xmlns:f="http://java.sun.com/jsf/core" xmlns:ui="http://java.sun.com/jsf/facelets" xmlns:a4j="http://richfaces.org/a4j"> <h:head></h:head> <h:form> <ui:insert name="create_form">  </ui:insert> <br /> <br /> <h:commandLink id="link" value="Name Converted"> <f:ajax event="click" listener="#{requestScope[beantt].convertNameToUpperCase2}" execute="dateOfExpense" render="dateOfExpense" /> </h:commandLink> </h:form> </ui:composition>

示例测试页：

<ui:composition xmlns="http://www.w3.org/1999/xhtml" xmlns:h="http://java.sun.com/jsf/html" xmlns:f="http://java.sun.com/jsf/core" xmlns:ui="http://java.sun.com/jsf/facelets" xmlns:a4j="http://richfaces.org/a4j"> <f:view> <h:body> <ui:composition template="testTemplate.xhtml"> <ui:param name="beantt" value="helloWorld" /> <ui:define name="create_form"> <h:panelGrid columns="3"> <h:outputLabel value="Name*:" for="itemName" /> <h:inputText size="20" value="#{helloWorld.name}" id="dateOfExpense"/> <h:outputText value="#{requestScope}" /> </h:panelGrid> </ui:define> </ui:composition> </h:body> </f:view> </ui:composition>

后端bean类:(不使用原型）

@Named("helloWorld") //@Model was not available in my project public class HelloWorldBean { private String name; //Getters and Setters Logger LOG = LoggerFactory.getLogger(HelloWorldBean.class); public void convertNameToUpperCase2(AjaxBehaviorEvent event) { LOG.debug("Inside Bean"); name = name.toUpperCase(); } }

更新豆类

@javax.faces.bean.ManagedBean(name="helloWorld") @javax.enterprise.context.RequestScoped public class HelloWorldBean { private String name; // Getters and Setters // Logger LOG = LoggerFactory.getLogger(HelloWorldBean.class); public void convertNameToUpperCase2(AjaxBehaviorEvent event) { // LOG.debug("Inside Bean"); name = name.toUpperCase(); } public String getName() { return name; } public void setName(String name) { this.name = name; } }

我还在请求范围中显示了所有可用变量，这有助于找出所查找的密钥是否实际可用。

<强>更新到目前为止，这是我的观察。如果您尝试连接@Named，@ Model（它不适用于UI，意味着无法在xhtmls中解析）。

CDI更像是将服务注入控制器或此处ManagedBean。

e.g。展示CDI的样本：

@Named("testCon") public class TestConsumer { public String convertNameToUpperCase2(String name) { // LOG.debug("Inside Bean"); return name.toUpperCase(); }

}

@ javax.faces.bean.ManagedBean（名称= “HelloWorld” 的） @ javax.enterprise.context.RequestScoped 公共类HelloWorldBean {

@Inject @Named("testCon") private TestConsumer test; private String name; // Getters and Setters // Logger LOG = LoggerFactory.getLogger(HelloWorldBean.class); public void convertNameToUpperCase2(AjaxBehaviorEvent event) { name = test.convertNameToUpperCase2(name); } public String getName() { return name; } public void setName(String name) { this.name = name; } }

如何在托盘模板上传递托管bean作为参数

2 个答案: