【发布时间】：2013-06-27 23:10:43
【问题描述】：
我正在使用 Hibernate 学习 Spring，并正在使用 JSF 作为前端框架创建电影租赁应用程序。
我的注册 bean 中有一个应用程序范围的托管属性，它是视图范围的。在将用户详细信息插入数据库的register() 方法中，我调用服务定位器实现bean 以获取对所需服务实现的引用。但是，当我调用服务定位器属性的 getter 时，我得到了 NPE。
以下是我的托管 bean...
注册 Bean
@ManagedBean
@ViewScoped
public class RegistrationBean extends BaseBean implements Serializable
{
private static final long serialVersionUID = -6449858513581500971L;
private String userID;
private String password;
private String firstName;
private String lastName;
private String email;
private String addressLine1;
private String addressLine2;
private String city;
private String state;
private String pincode;
public RegistrationBean() {
super();
}
// getter / setters...
public String register()
{
String nextPage = null;
try {
RegistrationDetails userDetails = ModelBuilder.populateRegistrationData(this);
// NPE at this line. getServiceLocator() returns null
int registrationID = getServiceLocator().getUserService().registerUser(userDetails);
nextPage = "success";
}
catch (RegistrationException e) {
LOGGER.error(e.getMessage());
}
return nextPage;
}
}
基础 Bean
public class BaseBean
{
@ManagedProperty("#{serviceLocator}")
protected IServiceLocator serviceLocator;
protected IServiceLocator getServiceLocator() {
return serviceLocator;
}
public void setServiceLocator(IServiceLocator serviceLocator) {
this.serviceLocator = serviceLocator;
}
}
服务定位器 Bean
@ManagedBean
@ApplicationScoped
public class ServiceLocator implements IServiceLocator
{
private static final String USER_SERVICE = "userService";
public ServiceLocator() {
super();
final ServletContext sc = FacesUtils.getServletContext();
this.webAppContext = WebApplicationContextUtils.getRequiredWebApplicationContext(sc);
this.userService = (IUserService) webAppContext.getBean(USER_SERVICE);
}
private ApplicationContext webAppContext;
private IUserService userService;
@Override
public IUserService getUserService() {
return userService;
}
public ApplicationContext getWebAppContext() {
return webAppContext;
}
}
这是在我的 Eclipse 控制台中看到的堆栈跟踪
Oct 14, 2012 10:28:39 PM com.sun.faces.lifecycle.InvokeApplicationPhase execute
WARNING: #{registrationBean.register}: java.lang.NullPointerException
javax.faces.FacesException: #{registrationBean.register}: java.lang.NullPointerException
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)
at com.sun.faces.lifecycle.Phase.doPhase(Phase.java:101)
at com.sun.faces.lifecycle.LifecycleImpl.execute(LifecycleImpl.java:118)
at javax.faces.webapp.FacesServlet.service(FacesServlet.java:593)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:305)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:222)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:123)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:472)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:168)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:99)
at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:929)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:118)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:407)
at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1002)
at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:585)
at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:312)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1110)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:603)
at java.lang.Thread.run(Thread.java:722)
Caused by: javax.faces.el.EvaluationException: java.lang.NullPointerException
at javax.faces.component.MethodBindingMethodExpressionAdapter.invoke(MethodBindingMethodExpressionAdapter.java:102)
at com.sun.faces.application.ActionListenerImpl.processAction(ActionListenerImpl.java:102)
... 23 more
Caused by: java.lang.NullPointerException
at com.clixflix.managedbeans.RegistrationBean.register(RegistrationBean.java:118)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:601)
at org.apache.el.parser.AstValue.invoke(AstValue.java:278)
at org.apache.el.MethodExpressionImpl.invoke(MethodExpressionImpl.java:274)
at com.sun.faces.facelets.el.TagMethodExpression.invoke(TagMethodExpression.java:105)
at javax.faces.component.MethodBindingMethodExpressionAdapter.invoke(MethodBindingMethodExpressionAdapter.java:88)
... 24 more
我正在使用
- JSF 2.1 (Mojarra)
- 休眠 4.1
- 春季 3.2
- 雄猫 7
- Eclipse 3.7
如果我遗漏了什么，有人可以指出吗？
更新：Spring配置文件
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans-2.5.xsd">
<bean id="sessionFactory" class="org.springframework.orm.hibernate4.LocalSessionFactoryBean">
<property name="configLocation" value="/WEB-INF/hibernate.cfg.xml" />
</bean>
<bean id="hibernateTemplate" class="org.springframework.orm.hibernate3.HibernateTemplate">
<property name="sessionFactory" ref="sessionFactory" />
</bean>
<bean id="userDAO" class="com.clixflix.dao.impl.UserDAOImpl">
<constructor-arg index="0" ref="hibernateTemplate" />
</bean>
<bean id="userService" class="com.clixflix.services.impl.UserService">
<constructor-arg index="0" ref="userDAO" />
</bean>
</beans>
【问题讨论】：
-
@BalusC - 正如我所说，我正在学习 Spring + Hibernate，所以我的设计将是临时的。但是不，我的服务定位器不是 spring bean。它封装的用户服务属性是一个spring bean。我已经添加了我的 spring 配置文件。我确实读过一篇使用 JSF2.0 和 Spring MVC 的文章，但它有点令人困惑，所以现在我只是使用依赖注入和 Spring ORM 为休眠部分提供的休眠模板。
标签： spring jsf-2 nullpointerexception