无法将请求从 JSF 重定向到 Spring答案

【问题标题】：unable to redirect a request from JSF to Spring无法将请求从 JSF 重定向到 Spring
【发布时间】：2014-10-18 22:40:52
【问题描述】：

我是 spring 和 jsf 的新手，我正在尝试在提交到 spring 控制器类之后重定向我的 JSF 页面。但是，当它在我的控制器方法中调用另一个方法时，我可以重定向，遇到空指针异常。请指教。

谢谢，维诺特

<?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:ui="http://java.sun.com/jsf/facelets"
      xmlns:h="http://java.sun.com/jsf/html"
      xmlns:f="http://java.sun.com/jsf/core">
    <h:head>
    </h:head>
    <h:body>

        <center>
            <ui:composition template="/BasicTemplate.xhtml">
                <ui:define name="content">
                    <h:form>
                        <h:panelGrid columns="2" bgcolor="yellow" border="10"
                                     style="height: 127px; width: 481px;  ">
                            <f:facet name="header">
                                <h:outputText value="LOGIN PAGE"></h:outputText>
                            </f:facet>
                            <h:outputText id="user" value="Username"></h:outputText>
                            <h:inputText id="userName" label="userName" value="#{LoginForm.userName}" required="true"
                                         requiredMessage="Username is mandatory" validatorMessage="username is mandatory">
                            </h:inputText>
                            <h:message for="userName" style="color: red;" />
                            <br></br>
                            <h:outputText id="passWord" value="Password"></h:outputText>
                            <h:inputSecret id="pass" value="#{LoginForm.passWord}" required="true"
                                           requiredMessage="Password is mandtory">
                                <f:validateLength minimum="5" maximum="10" />
                            </h:inputSecret>
                            <h:message for="pass" style="color: red;" />
                        </h:panelGrid>
                        <h:commandButton value="Login" action="#{loginController.validatelogin(LoginForm)}"/>
                    </h:form>
                </ui:define>
            </ui:composition>
        </center>
    </h:body>

</html>

下面是我的控制器类

package com.BillingSolution.Login;

import com.BillingSolution.Form.LoginForm;
import javax.faces.bean.ManagedBean;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;


@Controller

public class LoginController {

    @Autowired
    private LoginService loginservice;

    @RequestMapping("/loginvalidate")
    public String validatelogin(LoginForm request) {
        String result = loginservice.ValidateLogin(request);
        return result;
    }

    @RequestMapping("/adduser")
    public String adduser(LoginForm param) {
         String result = loginservice.adduser(param);
         return result;
    }

}

下面是我的 jsf 配置文件

<faces-config version="2.1"
              xmlns="http://java.sun.com/xml/ns/javaee"
              xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
              xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-facesconfig_2_1.xsd">
    <application>
    <el-resolver>org.springframework.web.jsf.el.SpringBeanFacesELResolver</el-resolver>
</application>
    <managed-bean>
        <managed-bean-name>LoginForm</managed-bean-name>
        <managed-bean-class>com.BillingSolution.Form.LoginForm</managed-bean-class>
        <managed-bean-scope>session</managed-bean-scope>
    </managed-bean>
    <navigation-rule>
        <display-name>/login.xhtml</display-name>
        <from-view-id>/login.xhtml</from-view-id>
        <navigation-case>
            <from-outcome>errorLogin</from-outcome>
            <to-view-id>footer.xhtml</to-view-id>
        </navigation-case>
    </navigation-rule>
    <navigation-rule>
        <display-name>/login.xhtml</display-name>
        <from-view-id>/login.xhtml</from-view-id>
        <navigation-case>
            <from-outcome>successLogin</from-outcome>
            <to-view-id>header.xhtml</to-view-id>
            <redirect/>
        </navigation-case>
    </navigation-rule>

</faces-config>

下面是web.xml

<web-app version="3.0" xmlns="http://java.sun.com/xml/ns/javaee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd">

    <context-param>
        <param-name>contextConfigLocation</param-name>
        <param-value>/WEB-INF/applicationContext.xml</param-value>
    </context-param>
    <context-param>
        <param-name>javax.faces.PROJECT_STAGE</param-name>
        <param-value>Development</param-value>
    </context-param>
    <listener>
        <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
    </listener>
    <servlet>
        <servlet-name>dispatcher</servlet-name>
        <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
        <load-on-startup>2</load-on-startup>
    </servlet>
    <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>dispatcher</servlet-name>
        <url-pattern>/</url-pattern>
    </servlet-mapping>
    <servlet-mapping>
        <servlet-name>Faces Servlet</servlet-name>
        <url-pattern>/</url-pattern>
    </servlet-mapping>
    <session-config>
        <session-timeout>
            30
        </session-timeout>
    </session-config>
    <welcome-file-list>
        <welcome-file>login.xhtml</welcome-file>
    </welcome-file-list>
</web-app>

调度程序-servlet.xml

    <mvc:annotation-driven/>  
    <mvc:default-servlet-handler/>
    <context:annotation-config />
    <context:component-scan base-package="com.BillingSolution" />

    <bean class="org.springframework.web.servlet.mvc.support.ControllerClassNameHandlerMapping"/>
    <bean id="jspViewResolver"
          class="org.springframework.web.servlet.view.InternalResourceViewResolver">
        <property name="viewClass"
                  value="org.springframework.web.servlet.view.JstlView" />
        <property name="prefix" value="/WEB-INF/jsp/" />
        <property name="suffix" value=".jsp" />
    </bean>

    <bean id="messageSource"
          class="org.springframework.context.support.ReloadableResourceBundleMessageSource">
        <property name="basename" value="classpath:messages" />
        <property name="defaultEncoding" value="UTF-8" />
    </bean>

    <bean id="propertyConfigurer"
          class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer"
          p:location="/WEB-INF/jdbc.properties" />

    <bean id="dataSource"
          class="com.BillingSolution.MyCustomBasicDataSource.MyCustomBasicDataSource" destroy-method="close"
          p:driverClassName="${jdbc.driverClassName}"
          p:url="${jdbc.databaseurl}" p:username="${jdbc.username}"
          p:password="${jdbc.password}" />

    <bean id="sessionFactory" class="org.springframework.orm.hibernate4.LocalSessionFactoryBean">
        <property name="dataSource" ref="dataSource" />
        <property name="configLocation">
            <value>classpath:hibernate.cfg.xml</value>

        </property>
        <property name="hibernateProperties">
            <props>
                <prop key="hibernate.dialect">${jdbc.dialect}</prop>
                <prop key="hibernate.show_sql">true</prop>
                <prop key="hibernate.jdbc.use_get_generated_keys">true</prop>
            </props>
        </property>
    </bean>
     <!-- Hibernate Transaction Manager -->
      <bean id="transactionManager" class="org.springframework.orm.hibernate4.HibernateTransactionManager">
      <property name="sessionFactory" ref="sessionFactory"/>
      </bean>
      <!-- Activates annotation based transaction management -->
         <tx:annotation-driven transaction-manager="transactionManager"/>
      <!--
       Most controllers will use the ControllerClassNameHandlerMapping above, but
       for the index controller we are using ParameterizableViewController, so we must
       define an explicit mapping for it.
       -->  
        <bean id="urlMapping" class="org.springframework.web.servlet.handler.SimpleUrlHandlerMapping" >
        <property name="mappings">
            <props>
                <prop key="index.htm">indexController</prop>
            </props>
        </property>
        </bean>
         <bean name="indexController"
          class="org.springframework.web.servlet.mvc.ParameterizableViewController"
          p:viewName="index" />

       </beans>

登录服务

package com.BillingSolution.Login;

import com.BillingSolution.Form.LoginForm;

public interface LoginService {

    public String ValidateLogin (LoginForm request);
    public String adduser(LoginForm request);

}

登录服务实现

package com.BillingSolution.Login;

import com.BillingSolution.Form.LoginForm;
import com.BillingSolution.User.LoginDAO;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;


@Service
public class LoginServiceImpl implements LoginService {

    @Autowired
    private LoginDAO logindao;

    @Transactional
    @Override
    public String ValidateLogin(LoginForm request) {
        String userName = request.getUserName();
        String passWord = request.getPassWord();
        System.out.println("=======================================" + userName);
        String result = logindao.loginvalidation(userName, passWord);
        return result;
    }

    @Transactional
    @Override
    public String adduser(LoginForm request) {
        String userName = request.getUserName();
        String passWord = request.getPassWord();
        System.out.println("=======================================" + userName);
        String result = logindao.adduser(userName, passWord);
        return result;
    }
}

applicationContext.xml

<?xml version='1.0' encoding='UTF-8' ?>
<!-- was: <?xml version="1.0" encoding="UTF-8"?> -->
<beans xmlns="http://www.springframework.org/schema/beans"
   xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
   xmlns:p="http://www.springframework.org/schema/p"
   xmlns:aop="http://www.springframework.org/schema/aop"
   xmlns:tx="http://www.springframework.org/schema/tx"
   xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-4.0.xsd
   http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop.xsd

   http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-4.0.xsd">

  <!-- ADD PERSISTENCE SUPPORT HERE (jpa, hibernate, etc) -->
     <bean id="loginservice" class="com.BillingSolution.Login.LoginServiceImpl"></bean>

错误：

<Aug 28, 2014 12:01:57 AM SGT> <Warning>     <javax.enterprise.resource.webcontainer.jsf.lifecycle> <BEA-000000> <#  {loginController.validatelogin(LoginForm)}: javax.el.PropertyNotFoundException:  //C:/Users/Vinoth/Documents/NetBeansProjects/BillingSolution/build/web/login.xhtml @33,110    action="#{loginController.validatelogin(LoginForm)}": Target Unreachable, identifier  'loginController' resolved to null
  javax.faces.FacesException: #{loginController.validatelogin(LoginForm)}:  javax.el.PropertyNotFoundException:  //C:/Users/Vinoth/Documents/NetBeansProjects/BillingSolution/build/web/login.xhtml @33,110  action="#{loginController.validatelogin(LoginForm)}": Target Unreachable, identifier  'loginController' resolved to null
    at    com.sun.faces.application.ActionListenerImpl.processAction(ActionListenerImpl.java:118)
at javax.faces.component.UICommand.broadcast(UICommand.java:315)
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)
    Truncated. see log file for complete stacktrace
Caused By: javax.faces.el.EvaluationException: javax.el.PropertyNotFoundException: //C:/Users/Vinoth/Documents/NetBeansProjects/BillingSolution/build/web/login.xhtml @33,110 action="#{loginController.validatelogin(LoginForm)}": Target Unreachable, identifier 'loginController' resolved to null
at javax.faces.component.MethodBindingMethodExpressionAdapter.invoke(MethodBindingMethodExpressionAdapter.java:95)
at com.sun.faces.application.ActionListenerImpl.processAction(ActionListenerImpl.java:102)
at javax.faces.component.UICommand.broadcast(UICommand.java:315)
at javax.faces.component.UIViewRoot.broadcastEvents(UIViewRoot.java:794)
at javax.faces.component.UIViewRoot.processApplication(UIViewRoot.java:1259)
Truncated. see log file for complete stacktrace
   Caused By: javax.el.PropertyNotFoundException: //C:/Users/Vinoth/Documents/NetBeansProjects/BillingSolution/build/web/login.xhtml @33,110 action="#{loginController.validatelogin(LoginForm)}": Target Unreachable, identifier 'loginController' resolved to null
at com.sun.faces.facelets.el.TagMethodExpression.invoke(TagMethodExpression.java:107)
at javax.faces.component.MethodBindingMethodExpressionAdapter.invoke(MethodBindingMethodExpressionAdapter.java:88)
at  com.sun.faces.application.ActionListenerImpl.processAction(ActionListenerImpl.java:102)
at javax.faces.component.UICommand.broadcast(UICommand.java:315)
at javax.faces.component.UIViewRoot.broadcastEvents(UIViewRoot.java:794)
Truncated. see log file for complete stacktrace

【问题讨论】：

看起来你 loginservice 没有自动连线。添加 loginservice 实现和 context.xml
@Jens ，如果我使用 JSP 使用此“
"
，此代码可以正常工作
查看 here 以获取示例 spring jsf 集成。
我很烦恼如果没有 Spring EL 解析器，这一切怎么能工作......

标签： spring jsf jsf-2 primefaces

【解决方案1】：

在您的项目中，JSF 不知道 Spring 托管 bean。为此，您必须配置委托给 Spring 根 WebApplicationContext 的 JSF ELResolver，解析对 Spring 定义的 bean 的名称引用。

在您的 faces-config.xml 文件中配置此解析器，如下所示：

   <application>
     ...
     <el-resolver>org.springframework.web.jsf.el.SpringBeanFacesELResolver</el-resolver>
   </application>

然后，您的所有 JSF 表达式都可以隐式引用 Spring 管理的服务层 bean 的名称，例如在 JSF 管理的 bean 的属性值中：

<managed-bean>
     <managed-bean-name>myJsfManagedBean</managed-bean-name>
     <managed-bean-class>example.MyJsfManagedBean</managed-bean-class>
     <managed-bean-scope>session</managed-bean-scope>
     <managed-property>
       <property-name>mySpringManagedBusinessObject</property-name>
       <value>#{mySpringManagedBusinessObject}</value>
     </managed-property>
   </managed-bean>
with "mySpringManagedBusinessObject" defined as Spring bean in applicationContext.xml:
   <bean id="mySpringManagedBusinessObject" class="example.MySpringManagedBusinessObject">
     ...
   </bean>

以上来自 Spring javadocs 本身。

在此之后，您可以从 LoginController 中删除 @ManagedBean 注释，因为 Spring 将管理它并创建它的 bean，将 LoginService 正确地注入其中。

然后，您可以使用其默认 bean 名称在 .xhtml 中引用 LoginController，如下所示：

<h:commandButton value="Login" action="#{loginController.validatelogin(LoginForm)}"/>

附带说明，您的项目中有许多违反命名约定的行为。您应该考虑重构为标准约定。

【讨论】：

嗨 Varun，感谢您的帮助，我已将 el-resolver 添加到 spring-config.xml 中，并在 application-context.xml 文件下添加了我的 LoginServieImpl 类的 bean，但我仍然遇到错误.请告知错误是“ javax.el.PropertyNotFoundException: //C:/Users/Vinoth/Documents/NetBeansProjects/BillingSolution/build/web/login.xhtml @33,110 action="#{loginController.validatelogin(LoginForm)}": Target无法访问，标识符“loginController”解析为空“
@Vinoth 您可以在尝试上述方法后发布您的代码吗？
@Vinoth 堆栈跟踪与代码不匹配