我是spring和jsf的新手，我在提交给spring控制器类之后尝试重定向我的JSF页面。我能够重定向，但是当它在我的控制器方法中调用另一个方法时，会遇到空指针异常。请指教。
谢谢， Vinoth
Login.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: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;
}
}
以下是我的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>
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>
分配器一servlet.xml中
<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>
login服务
package com.BillingSolution.Login;
import com.BillingSolution.Form.LoginForm;
public interface LoginService {
public String ValidateLogin (LoginForm request);
public String adduser(LoginForm request);
}
LoginServiceImpl
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;
}
}
的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
答案 0 :(得分：0)
在您的项目中，JSF不了解Spring托管bean。为此，您必须配置委托给Spring root WebApplicationContext的JSF ELResolver，解析对Spring定义的bean的名称引用。
在faces-config.xml文件中配置此解析程序，如下所示：
<application>
...
<el-resolver>org.springframework.web.jsf.el.SpringBeanFacesELResolver</el-resolver>
</application>
然后，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托管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>
以上内容来自Spring javadocs本身。
在此之后，您可以从@ManagedBean中删除LoginController注释，因为Spring将对其进行管理并创建其正确注入LoginService的bean。
然后，您可以使用其默认bean名称引用LoginController中的.xhtml，如下所示：
<h:commandButton value="Login" action="#{loginController.validatelogin(LoginForm)}"/>
另外，项目中存在许多违反命名约定的行为。您应该考虑重构标准约定。