[SPRING] 관리 속성의 getter를 호출 할 때 NPE

관리 속성의 getter를 호출 할 때 NPE

나는 Hibernate로 Spring을 배우고 있으며 JSF를 프론트 엔드 프레임 워크로 사용하여 영화 대여 애플리케이션을 만들고있다.

내가보기 범위가 내 등록 콩에서 응용 프로그램 범위 관리 속성이 있습니다. 데이터베이스에 사용자 정보를 삽입하는 register () 메서드에서 서비스 로케이터 구현 빈을 호출하여 필요한 서비스 구현에 대한 참조를 가져옵니다. 그러나 서비스 로케이터 등록 정보의 getter를 호출 할 때 NPE가 표시됩니다.

다음은 관리 빈즈입니다 ...

등록 빈

@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;
   }
}

베이스 콩

public class BaseBean
{
   @ManagedProperty("#{serviceLocator}")
   protected IServiceLocator serviceLocator;

   protected IServiceLocator getServiceLocator() {
      return serviceLocator;
   }

   public void setServiceLocator(IServiceLocator serviceLocator) {
      this.serviceLocator = serviceLocator;
   }
}

서비스 검색기 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;
   }
}

그리고 여기 내 이클립스 콘솔에서 볼 수있는 스택 추적이 있습니다.

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

나는 사용하고있다.

내가 누군가를 놓쳤다 고 지적 할 수 있었느냐?

업데이트 : Spring 설정 파일

<?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>

해결법

1. ==============================

   1.이 게시물을 통해 코드 작업을 할 수있었습니다. http://www.javacodegeeks.com/2012/04/jsf-2-primefaces-3-spring-3-hibernate-4.html

   이 게시물을 통해 코드 작업을 할 수있었습니다. http://www.javacodegeeks.com/2012/04/jsf-2-primefaces-3-spring-3-hibernate-4.html

   그러나 등록 범위를 뷰 범위로 유지하면 코드가 작동하지 않습니다. 아무도 내가 같은 이유를 알아낼 수있게 도와 줄 수 있습니까?

   업데이트 : ViewScope 문제에 대한 해결책을 찾았습니다. http://blog.harezmi.com.tr/spring-view-scope-for-jsf-2-users/

from https://stackoverflow.com/questions/12884822/npe-when-invoking-getter-of-managed-property by cc-by-sa and MIT license