警告:/index.xhtml @ 18,82 value ="## loginBean.email}":无法到达目标，标识符'loginBean'解析为null [英] Warning: /index.xhtml @18,82 value="#{loginBean.email}": Target Unreachable, identifier 'loginBean' resolved to null
本文介绍了警告:/index.xhtml @ 18,82 value ="## loginBean.email}":无法到达目标，标识符'loginBean'解析为null的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！
问题描述
我是JSF的新手，但遇到此错误，但我不知道如何解决. 我在网上阅读了一些类似的问题，但是没有一个可以解决我的问题.
I'm new in JSF and I got this error, but I don't know how to fix it. I read some similar issues online, but none of them could resolve mine.
这是我的课程:
index.xhtml
index.xhtml
<?xml version='1.0' encoding='UTF-8' ?>
<!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:h="http://xmlns.jcp.org/jsf/html"
xmlns:p="http://primefaces.org/ui"
lang="en-us">
<h:head>
<title>Welcome </title>
</h:head>
<h:body>
<center>
<p:outputLabel><h1>Welcome</h1></p:outputLabel>
<br/>
<h:form id="loginForm">
<p:panel id="loginPanel" header="Login" style="width: 360px;">
<p:panelGrid columns="2">
<p:outputLabel id="email_outputText" value="Email" for="email_inputText"/>
<p:inputText id="email_inputText" value="#{loginBean.email}"></p:inputText>
<p:outputLabel id="password_outputText" value="Password" for="password_inputText"/>
<p:password id="password_inputText" value="#{loginBean.password}" feedback="false"></p:password>
</p:panelGrid>
<br/>
<p:commandButton action="#{loginBean.MD5}" value="Login" update="loginForm"></p:commandButton>
</p:panel>
</h:form>
</center>
</h:body>
</html>
LoginBean.java
LoginBean.java
package beans.controller;
import java.io.Serializable;
import java.io.UnsupportedEncodingException;
import java.math.BigInteger;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
import java.util.logging.Level;
import java.util.logging.Logger;
import javax.annotation.ManagedBean;
import javax.enterprise.context.SessionScoped;
@ManagedBean(value="loginBean")
@SessionScoped
public class LoginBean implements Serializable{
/**
* attribute that will contain the password input by the user
*/
private String password;
/**
* attribute that will contain error message
*/
private String message;
/**
* attribute that will contain the user email input by the user
*/
private String email;
/**
* attribute that will contain the hash of password input by the user
* We remember that for security reasons password are stored in the DB in way that
* it can't be restored for any reasons
*/
private String hash_password;
/**
* getter method for attribute hash_password
* @return hash_password
*/
public String getHash_password() {
return hash_password;
}
/**
* setter method for hash_password
* @param hash_password
*/
public void setHash_password(String hash_password) {
this.hash_password = hash_password;
}
/**
* getter method for attribute password
* @return password
*/
public String getPassword() {
return password;
}
/**
* setter method for attribute password
* @param password
*/
public void setPassword(String password) {
this.password = password;
}
/**
* getter method for attribute message
* @return message
*/
public String getMessage() {
return message;
}
/**
* setter methos for attribute message
* @param message
*/
public void setMessage(String message) {
this.message = message;
}
/**
* getter method for attribute email
* @return email
*/
public String getEmail() {
return email;
}
/**
* setter method for attribute email
* @param email
*/
public void setEmail(String email) {
this.email = email;
}
/**
* Method that checks if the user exists inside the users database
* and it creates a new session
* @return String: it returns the page where we have to be readdressed
*/
public String login(){
//I check that the user exists inside the users database
boolean result=UserEJB.login(email,password);
if(result){
return "home";
}else{
return "login";
}
}
/**
* MD5 algorithm for encrypting password. We provide a clear password as input
* and as output we get a hashed function
* @param message
* @throws NoSuchAlgorithmException
*/
private void MD5(String password) throws UnsupportedEncodingException
{
try {
MessageDigest m=MessageDigest.getInstance("MD5");
m.update(password.getBytes(),0,password.length());
System.out.println("MD5: "+new BigInteger(1,m.digest()).toString(16));
} catch (NoSuchAlgorithmException ex) {
Logger.getLogger(LoginBean.class.getName()).log(Level.SEVERE, null, ex);
}
}
}
web.xml
<?xml version="1.0" encoding="UTF-8"?>
<web-app version="3.1" xmlns="http://xmlns.jcp.org/xml/ns/javaee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_3_1.xsd">
<context-param>
<param-name>javax.faces.PROJECT_STAGE</param-name>
<param-value>Development</param-value>
</context-param>
<servlet>
<servlet-name>Faces Servlet</servlet-name>
<servlet-class>javax.faces.webapp.FacesServlet</servlet-class>
<load-on-startup>1</load-on-startup>
</servlet>
<servlet-mapping>
<servlet-name>Faces Servlet</servlet-name>
<url-pattern>/faces/*</url-pattern>
</servlet-mapping>
<session-config>
<session-timeout>
30
</session-timeout>
</session-config>
<welcome-file-list>
<welcome-file>faces/index.xhtml</welcome-file>
</welcome-file-list>
</web-app>
当我运行它时，出现此错误:
And when I run it i got this error :
Warning: /index.xhtml @18,82 value="#{loginBean.email}": Target Unreachable, identifier 'loginBean' resolved to null
javax.el.PropertyNotFoundException: /index.xhtml @18,82 value="#{loginBean.email}": Target Unreachable, identifier 'loginBean' resolved to null
at com.sun.faces.facelets.el.TagValueExpression.getType(TagValueExpression.java:100)
at org.primefaces.util.ComponentUtils.getConverter(ComponentUtils.java:126)
at org.primefaces.renderkit.InputRenderer.getConvertedValue(InputRenderer.java:171)
at javax.faces.component.UIInput.getConvertedValue(UIInput.java:1045)
at javax.faces.component.UIInput.validate(UIInput.java:975)
at javax.faces.component.UIInput.executeValidate(UIInput.java:1248)
at javax.faces.component.UIInput.processValidators(UIInput.java:712)
at javax.faces.component.UIComponentBase.processValidators(UIComponentBase.java:1258)
at javax.faces.component.UIComponentBase.processValidators(UIComponentBase.java:1258)
at org.primefaces.component.panel.Panel.processValidators(Panel.java:287)
at javax.faces.component.UIForm.processValidators(UIForm.java:253)
at javax.faces.component.UIComponentBase.processValidators(UIComponentBase.java:1258)
at javax.faces.component.UIComponentBase.processValidators(UIComponentBase.java:1258)
at javax.faces.component.UIViewRoot.processValidators(UIViewRoot.java:1195)
at com.sun.faces.lifecycle.ProcessValidationsPhase.execute(ProcessValidationsPhase.java:76)
at com.sun.faces.lifecycle.Phase.doPhase(Phase.java:101)
at com.sun.faces.lifecycle.LifecycleImpl.execute(LifecycleImpl.java:198)
at javax.faces.webapp.FacesServlet.service(FacesServlet.java:646)
at org.apache.catalina.core.StandardWrapper.service(StandardWrapper.java:1682)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:318)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:160)
at org.apache.catalina.core.StandardPipeline.doInvoke(StandardPipeline.java:734)
at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:673)
at com.sun.enterprise.web.WebPipeline.invoke(WebPipeline.java:99)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:174)
at org.apache.catalina.connector.CoyoteAdapter.doService(CoyoteAdapter.java:415)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:282)
at com.sun.enterprise.v3.services.impl.ContainerMapper$HttpHandlerCallable.call(ContainerMapper.java:459)
at com.sun.enterprise.v3.services.impl.ContainerMapper.service(ContainerMapper.java:167)
at org.glassfish.grizzly.http.server.HttpHandler.runService(HttpHandler.java:201)
at org.glassfish.grizzly.http.server.HttpHandler.doHandle(HttpHandler.java:175)
at org.glassfish.grizzly.http.server.HttpServerFilter.handleRead(HttpServerFilter.java:235)
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:561)
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$Worker.doWork(AbstractThreadPool.java:565)
at org.glassfish.grizzly.threadpool.AbstractThreadPool$Worker.run(AbstractThreadPool.java:545)
at java.lang.Thread.run(Thread.java:745)
Caused by: javax.el.PropertyNotFoundException: Target Unreachable, identifier 'loginBean' resolved to null
at com.sun.el.parser.AstValue.getTarget(AstValue.java:174)
at com.sun.el.parser.AstValue.getType(AstValue.java:86)
at com.sun.el.ValueExpressionImpl.getType(ValueExpressionImpl.java:201)
at org.jboss.weld.el.WeldValueExpression.getType(WeldValueExpression.java:93)
at com.sun.faces.facelets.el.TagValueExpression.getType(TagValueExpression.java:98)
... 45 more
Severe: javax.el.PropertyNotFoundException: /index.xhtml @18,82 value="#{loginBean.email}": Target Unreachable, identifier 'loginBean' resolved to null
at com.sun.faces.facelets.el.TagValueExpression.getType(TagValueExpression.java:100)
at org.primefaces.util.ComponentUtils.getConverter(ComponentUtils.java:126)
at org.primefaces.renderkit.InputRenderer.getConvertedValue(InputRenderer.java:171)
at javax.faces.component.UIInput.getConvertedValue(UIInput.java:1045)
at javax.faces.component.UIInput.validate(UIInput.java:975)
at javax.faces.component.UIInput.executeValidate(UIInput.java:1248)
at javax.faces.component.UIInput.processValidators(UIInput.java:712)
at javax.faces.component.UIComponentBase.processValidators(UIComponentBase.java:1258)
at javax.faces.component.UIComponentBase.processValidators(UIComponentBase.java:1258)
at org.primefaces.component.panel.Panel.processValidators(Panel.java:287)
at javax.faces.component.UIForm.processValidators(UIForm.java:253)
at javax.faces.component.UIComponentBase.processValidators(UIComponentBase.java:1258)
at javax.faces.component.UIComponentBase.processValidators(UIComponentBase.java:1258)
at javax.faces.component.UIViewRoot.processValidators(UIViewRoot.java:1195)
at com.sun.faces.lifecycle.ProcessValidationsPhase.execute(ProcessValidationsPhase.java:76)
at com.sun.faces.lifecycle.Phase.doPhase(Phase.java:101)
at com.sun.faces.lifecycle.LifecycleImpl.execute(LifecycleImpl.java:198)
at javax.faces.webapp.FacesServlet.service(FacesServlet.java:646)
at org.apache.catalina.core.StandardWrapper.service(StandardWrapper.java:1682)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:318)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:160)
at org.apache.catalina.core.StandardPipeline.doInvoke(StandardPipeline.java:734)
at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:673)
at com.sun.enterprise.web.WebPipeline.invoke(WebPipeline.java:99)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:174)
at org.apache.catalina.connector.CoyoteAdapter.doService(CoyoteAdapter.java:415)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:282)
at com.sun.enterprise.v3.services.impl.ContainerMapper$HttpHandlerCallable.call(ContainerMapper.java:459)
at com.sun.enterprise.v3.services.impl.ContainerMapper.service(ContainerMapper.java:167)
at org.glassfish.grizzly.http.server.HttpHandler.runService(HttpHandler.java:201)
at org.glassfish.grizzly.http.server.HttpHandler.doHandle(HttpHandler.java:175)
at org.glassfish.grizzly.http.server.HttpServerFilter.handleRead(HttpServerFilter.java:235)
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:561)
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$Worker.doWork(AbstractThreadPool.java:565)
at org.glassfish.grizzly.threadpool.AbstractThreadPool$Worker.run(AbstractThreadPool.java:545)
at java.lang.Thread.run(Thread.java:745)
Caused by: javax.el.PropertyNotFoundException: Target Unreachable, identifier 'loginBean' resolved to null
at com.sun.el.parser.AstValue.getTarget(AstValue.java:174)
at com.sun.el.parser.AstValue.getType(AstValue.java:86)
at com.sun.el.ValueExpressionImpl.getType(ValueExpressionImpl.java:201)
at org.jboss.weld.el.WeldValueExpression.getType(WeldValueExpression.java:93)
at com.sun.faces.facelets.el.TagValueExpression.getType(TagValueExpression.java:98)
... 45 more
推荐答案
您为JSF managedbeans
替换这些:
import javax.annotation.ManagedBean;
import javax.enterprise.context.SessionScoped;
使用
import javax.faces.bean.ManagedBean;
import javax.faces.bean.SessionScoped;
您导入的是针对JAVAEE CDI的.
您可能正在使用Tomcat，这就是为什么它们不起作用的原因.
The ones you imported are for JAVAEE CDI.
You are probably using Tomcat, that is why they didnt work.
这篇关于警告:/index.xhtml @ 18,82 value ="## loginBean.email}":无法到达目标，标识符'loginBean'解析为null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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