導航JSF

早上好！我是新手。我有一個簡單的JSF應用程序。但它沒有按預期工作。這是我login.xhtml：導航JSF

<h:body> 
    <h:outputText value="Please enter your login and password"/> 
    <h:form id="loginForm"> 
     <h:panelGrid columns="2">  
       <h:outputText value="User name"/>     
       <h:inputText value="#{textBean.login}" required="true"/> 
       <h:outputText value="Password"/> 
       <h:inputSecret value="#{textBean.password}" required="true"/> 
       <h:commandButton value="Submit" action="#{textBean.doLogin}"/> 
     </h:panelGrid> 
    </h:form> 
</h:body>

這是我error.xhtml：

<h:body> 
    <h:outputText value="You have entered incorrect data"/> 
    <h:form id="errorForm">  
       <h:commandLink value="Back to login page" action="#{TextBean.backToLogin}"/> 
    </h:form> 
</h:body>

這是我的bean類TextBean.java：

公共類TextBean實現Serializable {

private static final long serialVersionUID = 1L; 

private String login; 

private String password; 

public String getLogin() { 
    return login; 
} 

public void setLogin(String login) { 
    this.login = login; 
} 

public String getPassword() { 
    return password; 
} 

public void setPassword(String password) { 
    this.password = password; 
} 

public String doLogin() { 
    if ("admin".equals(login) && "mypass".equals(password)) { 
     return "welcome"; 
    } else { 
     return "error"; 
    } 

} 

public String backToLogin() { 
     return "login"; 
}

}

爲什麼錯誤頁面不會回到登錄頁面？當你點擊鏈接「返回登錄頁面」時，我收到異常。我究竟做錯了什麼？這是我的例外：

 The server encountered an internal error() that prevented it from fulfilling this request. 
javax.servlet.ServletException: javax.el.PropertyNotFoundException: /error.xhtml @14,80 action="#{TextBean.doMyLogin}": Target Unreachable, identifier 'TextBean' resolved to null 
    javax.faces.webapp.FacesServlet.service(FacesServlet.java:521) 
javax.faces.el.EvaluationException: javax.el.PropertyNotFoundException: /error.xhtml @14,80 action="#{TextBean.doMyLogin}": Target Unreachable, identifier 'TextBean' resolved to null 
    javax.faces.component.MethodBindingMethodExpressionAdapter.invoke(MethodBindingMethodExpressionAdapter.java:95) 
    com.sun.faces.application.ActionListenerImpl.processAction(ActionListenerImpl.java:102) 
    javax.faces.component.UICommand.broadcast(UICommand.java:315) 
    javax.faces.component.UIViewRoot.broadcastEvents(UIViewRoot.java:787) 
    javax.faces.component.UIViewRoot.processApplication(UIViewRoot.java:1252) 
    com.sun.faces.lifecycle.InvokeApplicationPhase.execute(InvokeApplicationPhase.java:81) 
    com.sun.faces.lifecycle.Phase.doPhase(Phase.java:101) 
    com.sun.faces.lifecycle.LifecycleImpl.execute(LifecycleImpl.java:118) 
    javax.faces.webapp.FacesServlet.service(FacesServlet.java:508) 
javax.el.PropertyNotFoundException: /error.xhtml @14,80 action="#{TextBean.doMyLogin}": Target Unreachable, identifier 'TextBean' resolved to null 
    com.sun.faces.facelets.el.TagMethodExpression.invoke(TagMethodExpression.java:107) 
     javax.faces.component.MethodBindingMethodExpressionAdapter.invoke(MethodBindingMethodExpressionAdapter.java:88) 
    com.sun.faces.application.ActionListenerImpl.processAction(ActionListenerImpl.java:102) 
    javax.faces.component.UICommand.broadcast(UICommand.java:315) 
    javax.faces.component.UIViewRoot.broadcastEvents(UIViewRoot.java:787) 
    javax.faces.component.UIViewRoot.processApplication(UIViewRoot.java:1252) 
    com.sun.faces.lifecycle.InvokeApplicationPhase.execute(InvokeApplicationPhase.java:81) 
    com.sun.faces.lifecycle.Phase.doPhase(Phase.java:101) 
    com.sun.faces.lifecycle.LifecycleImpl.execute(LifecycleImpl.java:118) 
    javax.faces.webapp.FacesServlet.service(FacesServlet.java:508)

請幫助我，親愛的朋友們！任何幫助將不勝感激。

來源

2011-09-21 Michael

除了具體問題，爲什麼你不只是顯示在''同樣的形式的錯誤信息？應儘量避免POST請求上的向前導航。你可以在這篇文章中找到一些指針：http://balusc.blogspot.com/2011/09/communication-in-jsf-20.html – BalusC

@BalusC - 好文章:) –

你的豆的名字是textBean而不是TextBean。這就是爲什麼JSF無法解決它：identifier 'TextBean' resolved to null

來源

2011-09-21 14:45:05

非常感謝！非常愚蠢的錯誤... – Michael

@Andrei - 不客氣，它發生在每個人:) –

@Andrei看來你可以接受這個答案。 – Andrey

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