早上好!我是一个初学者。我有一个简单的JSF应用程序,但它并没有按照预期工作。 这是我的login.xhtml:
<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>
这是我的error.xhtml文件:
<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>
这是我的Java Bean类TextBean.java: public class TextBean实现了Serializable接口 {
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";
}
为什么错误页面不能返回登录页面?当您点击“返回登录页面”链接时,会出现异常。我做错了什么? 这是我的异常:
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)
亲爱的朋友们,请帮帮我!任何帮助都将不胜感激。
该内容与IT技术无关。
<h:message>
在同一表单中显示错误消息呢?应尽量避免在POST请求中进行前向导航。您可以在这篇文章中找到一些指针:http://balusc.blogspot.com/2011/09/communication-in-jsf-20.html - BalusC