找不到ManagedBean属性 [英] ManagedBean property not found

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问题描述

在我的Web应用程序中，当我单击登录链接时，Tomcat Web服务器将引发以下异常:

In my webapp, when I click on the login link, the Tomcat webserver throws the following exception:

exception
javax.servlet.ServletException: /aluno_jsf.xhtml: Property 'logout' not found on type
br.com.aluno.controller.LoginMB

javax.faces.webapp.FacesServlet.service(FacesServlet.java:422)

root cause
javax.el.ELException: /aluno_jsf.xhtml: Property 'logout' not found on type
br.com.aluno.controller.LoginMB
[...]

这是我的@ManagedBean:

Here's my @ManagedBean:

package br.com.aluno.controller;

import java.io.Serializable;
import java.util.Collection;
import javax.annotation.PostConstruct;
import javax.faces.bean.ManagedBean;
import javax.faces.context.FacesContext;
import javax.servlet.http.HttpSession;
import br.com.aluno.dao.DaoFactory;
import br.com.aluno.entity.Usuario;
import br.com.aluno.util.JsfUtil;

@ManagedBean
public class LoginMB implements Serializable {
private static final long serialVersionUID = 6667329439219329074L;

private Usuario usuario;

@PostConstruct
public void init() {
    usuario = new Usuario();
}

public void logar() {
    try {
        Collection<Usuario> usuarios = DaoFactory
                .getDAOFactory(DaoFactory.JPA).getUsuarioDao()
                .validarLogin(usuario);
        if (usuarios != null && usuarios.size() == 1) {

            usuario = usuarios.iterator().next();

            HttpSession session = (HttpSession) FacesContext
                    .getCurrentInstance().getExternalContext()
                    .getSession(true);
            if (session != null) {
                session.setAttribute("usuario", usuario);
                session.setAttribute("usuarioTipo", usuario.getClass()
                        .getName());
            }
        } else {
            JsfUtil.addErrorMessage("Login ou senha invalida",
                    "Login ou senha invalida");
        }
    } catch (Exception e) {
        JsfUtil.addFatalMessage("Entre em contato com o administrador",
                e.getMessage());
    }
}

public String logout() {
    HttpSession session = (HttpSession) FacesContext.getCurrentInstance()
            .getExternalContext().getSession(false);
    if (session != null) {
        session.invalidate();
    }
    return "/login?faces-redirect=true";
}

public Usuario getUsuario() {
    return usuario;
}

public void setUsuario(Usuario usuario) {
    this.usuario = usuario;
}
}

我在index.html中有一个链接，该链接重定向到以下login.xhtml:

I have a link in a index.html which redirects to the following login.xhtml:

<ui:decorate 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:p="http://primefaces.org/ui" template="/aluno_jsf.xhtml">

<ui:define name="conteudo">
    <h:form rendered="#{sessionScope.usuario == null}">
        <h3>Login</h3>
        <p:messages id="messages" showDetail="true" autoUpdate="true" />
        <h:panelGrid columns="2">
            <p:outputLabel for="login" value="Login:" />
            <p:inputText id="login" value="#{loginMB.usuario.login}" required="true" 
requiredMessage="Digite um login" />
            <p:outputLabel for="senha" value="Senha:" />
            <p:password id="senha" value="#{loginMB.usuario.senha}" required="true" 
requiredMessage="Digite uma senha" />
            <p:commandButton action="#{loginMB.logar}" value="Logar" ajax="false" />
        </h:panelGrid>
    </h:form>
</ui:define>

验证后，应显示以下页面:

After validation, the following pages should be rendered:

<!DOCTYPE html>
<html 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:p="http://primefaces.org/ui" >
<h:head>
<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1" />
<title>aluno_jsf</title>
</h:head>
<h:body>
<f:view>
    <h:form>
        <p:menubar
            rendered="#{sessionScope.usuarioTipo == 'br.com.aluno.entity.Administrador'}">
            <p:menuitem url="/administrador/cadastroCurso.xhtml"
value="Cadastro de curso" />
            <p:menuitem url="/administrador/cadastroDisciplina.xhtml" 
value="Cadastro de disciplinas" />
            <p:menuitem url="/administrador/cadastroAluno.xhtml" 
value="Cadastro de alunos" />
            <p:menuitem url="/administrador/atribuiNota.xhtml" 
value="Atribuicao de notas para alunos" />
            <p:menuitem action="#{loginMB.logout}" value="Logout" />
        </p:menubar>
        <p:menubar
rendered="#{sessionScope.usuarioTipo == 'br.com.aluno.entity.Aluno'}">
            <p:menuitem url="/aluno/nota.xhtml" value="Consulta de notas" />
            <p:menuitem url="/aluno/senha.xhtml" value="Alteracao de senha" />
            <p:menuitem action="#{loginMB.logout}" value="Logout" />
        </p:menubar>
    </h:form>
    <ui:insert name="conteudo">
    conteudo
    </ui:insert>
</f:view>
</h:body>
</html>

由于我正在适应此Web应用程序-之前我已经有一些错误的配置-有人知道现在发生了什么吗?

Since I'm adapting this web app - and I've already got some misconfigurations before - does anyone knows what's happening now?

谢谢.

如您所问，她是新的例外:

As you asked, her's the new exception:

message Could not initialize class br.com.fiap.aluno.util.JpaUtil

description The server encountered an internal error (Could not initialize class     br.com.fiap.aluno.util.JpaUtil) that prevented it from fulfilling this request.

exception

javax.servlet.ServletException: Could not initialize class br.com.fiap.aluno.util.JpaUtil
javax.faces.webapp.FacesServlet.service(FacesServlet.java:422)

root cause

java.lang.NoClassDefFoundError: Could not initialize class br.com.fiap.aluno.util.JpaUtil
br.com.fiap.aluno.dao_jpa.JpaUsuarioDao.validarLogin(JpaUsuarioDao.java:46)
br.com.fiap.aluno.controller.LoginMB.logar(LoginMB.java:30)
sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
java.lang.reflect.Method.invoke(Method.java:601)
javax.el.BeanELResolver.invoke(BeanELResolver.java:484)
javax.el.CompositeELResolver.invoke(CompositeELResolver.java:161)
org.apache.el.parser.AstValue.getValue(AstValue.java:159)
org.apache.el.ValueExpressionImpl.getValue(ValueExpressionImpl.java:189)
com.sun.faces.facelets.el.ELText$ELTextVariable.toString(ELText.java:214)
com.sun.faces.facelets.compiler.AttributeInstruction.write(AttributeInstruction.java:89)
com.sun.faces.facelets.compiler.UIInstructions.encodeBegin(UIInstructions.java:82)
    com.sun.faces.renderkit.html_basic.HtmlBasicRenderer.encodeRecursive(HtmlBasicRenderer.java:302)
com.sun.faces.renderkit.html_basic.GridRenderer.renderRow(GridRenderer.java:185)
com.sun.faces.renderkit.html_basic.GridRenderer.encodeChildren(GridRenderer.java:129)
javax.faces.component.UIComponentBase.encodeChildren(UIComponentBase.java:845)
javax.faces.component.UIComponent.encodeAll(UIComponent.java:1756)
javax.faces.render.Renderer.encodeChildren(Renderer.java:168)
javax.faces.component.UIComponentBase.encodeChildren(UIComponentBase.java:845)
javax.faces.component.UIComponent.encodeAll(UIComponent.java:1756)
javax.faces.component.UIComponent.encodeAll(UIComponent.java:1759)
javax.faces.component.UIComponent.encodeAll(UIComponent.java:1759)
  com.sun.faces.application.view.FaceletViewHandlingStrategy.renderView(FaceletViewHandlingStrategy.java:401)
com.sun.faces.application.view.MultiViewHandler.renderView(MultiViewHandler.java:131)
com.sun.faces.lifecycle.RenderResponsePhase.execute(RenderResponsePhase.java:121)
com.sun.faces.lifecycle.Phase.doPhase(Phase.java:101)
com.sun.faces.lifecycle.LifecycleImpl.render(LifecycleImpl.java:139)
javax.faces.webapp.FacesServlet.service(FacesServlet.java:410)

note The full stack trace of the root cause is available in the Apache Tomcat/7.0.29 logs.

我会尝试修复它，但如果您能提供一些提示，我将不胜感激.

I'll try to fix it, but I appreciate if you could give some hints.

推荐答案

javax.el.E​​LException:/aluno_jsf.xhtml:在类型上找不到属性注销" br.com.aluno.controller.LoginMB

javax.el.ELException: /aluno_jsf.xhtml: Property 'logout' not found on type br.com.aluno.controller.LoginMB

这表明#{loginMB.logout}被评估为ValueExpression而不是MethodExpression.

This suggests that the #{loginMB.logout} is been evaluated as a ValueExpression instead of as a MethodExpression.

例如，如果您使用的是<h:outputText value="#{loginMB.logout}" />，或者什至由于缺少或不正确的XML名称空间声明或包含以下内容的JAR文件而无法解析<x:someComponent action="#{loginMB.logout}" />后面的x名称空间时，就会发生这种情况被包含在运行时类路径中.

That can for example happen if you're using <h:outputText value="#{loginMB.logout}" />, or even when the x namespace behind <x:someComponent action="#{loginMB.logout}" /> can't be resolved due to missing or incorrect XML namespace declaration or the JAR file containing the components not being included in the runtime classpath.

该原因在到目前为止发布的代码中不可见，但是我最好的猜测是您没有正确使用Facelets模板.该代码显示了<ui:decorate>的奇怪用例.前往此答案以了解如何正确使用模板组成:

The cause is not visible in the code posted so far, but with my best guess you're not using Facelets templating properly. The code shows strange use case of <ui:decorate>. Head to this answer to learn how to properly use template compositions: How to include another XHTML in XHTML using JSF 2.0 Facelets?

这篇关于找不到ManagedBean属性的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！

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