얻기 javax.faces.FacesException : java.lang.NullPointerException이

나는 다음과 같이 웹 응용 프로그램을 개발하고 :얻기 javax.faces.FacesException : java.lang.NullPointerException이

글래스 피시 V3.1.2
이클립스 주노 SR2
JPA EclipseLink2.0
JSF 2.0

일반 사용자와 관리자 사용자에 대해 다른 페이지 집합이 있습니다. 로그인 중에 페이지 필터를 설정하려고 할 때 로그인 빈에서이 오류가 발생합니다. javax.faces.FacesException : # {loginBean.login} : java.lang.NullPointerException

전체 로그인 코드가이 부분없이 작동합니다.

if (uGDB.validateGroup(username, adminGroup)) { 
       return "home.jsf?faces-redirect=true&amp;includeViewParams=true"; 
      } 
      return "normalHome.jsf?faces-redirect=true&amp;includeViewParams=true"

;

내가 여기서하려는 것은 로그인 한 사용자의 그룹 ID를 가져와 관리자인지 확인하는 것입니다. 따라서 사용자를 해당 페이지로 안내하고 싶습니다. 이것은 admin 사용자와 일반 사용자를 위해 다른 페이지 집합을 가지고 있기 때문입니다. 최종 사용자가 필요로하지 않기 때문에 Glassfish Realms를 사용하고 싶지 않습니다.

누군가 내가 잘못 가고있는 부분을 식별하는 데 도움을 줄 수 있습니까? (어리석은 실수를 저를 용서해주세요. 나는 그런 개발을 시작하고 있습니다.) 많은 감사드립니다! 다음은

는

package beans; 

import java.io.Serializable; 

import javax.ejb.EJB; 
import javax.faces.application.FacesMessage; 
import javax.faces.bean.ManagedBean; 
import javax.faces.bean.RequestScoped; 
import javax.faces.context.FacesContext; 

import ejb.UserDaoBean; 
import ejb.UserGroupDaoBean; 

import model.User; 

@ManagedBean(name = "loginBean") 
@RequestScoped 
public class LoginBean implements Serializable { 

    /** 
    * 
    */ 
    private static final long serialVersionUID = 1L; 

    @EJB 
    private UserDaoBean uDB; 
    private UserGroupDaoBean uGDB; 
    private User userId; 

    private int adminGroup = 1; 

    private String username; 

    public String getUsername() { 
     return username; 
    } 

    public void setUsername(String username) { 
     this.username = username; 
    } 

    public String login() { 
     FacesContext context = FacesContext.getCurrentInstance(); 

     if (uDB.validateUser(username)) { 
      userId = uDB.findUser(username); 

      context.getExternalContext().getSessionMap().put("userId", userId); 
      if (uGDB.validateGroup(username, adminGroup)) { 
       return "home.jsf?faces-redirect=true&amp;includeViewParams=true"; 
      } 
      return "normalHome.jsf?faces-redirect=true&amp;includeViewParams=true"; 

     } else { 
      FacesMessage message = new FacesMessage(); 
      message.setSeverity(FacesMessage.SEVERITY_ERROR); 
      message.setSummary("Username doesn't exists! OR User is trying to login from someone else's account"); 
      context.addMessage("", message); 
      return null; 
     } 
    } 

    public String logout() { 
     FacesContext.getCurrentInstance().getExternalContext() 
       .invalidateSession(); 
     return "logout.jsf?faces-redirect=true"; 
    } 

}

은 글래스 피시 로그에서 전체 오류 스택 내 loginBean 코드입니다

WARNING: #{loginBean.login}: java.lang.NullPointerException 
javax.faces.FacesException: #{loginBean.login}: 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.StandardWrapper.service(StandardWrapper.java:1550) 
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:281) 
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:175) 
    at org.apache.catalina.core.StandardPipeline.doInvoke(StandardPipeline.java:655) 
    at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:595) 
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:161) 
    at org.apache.catalina.connector.CoyoteAdapter.doService(CoyoteAdapter.java:331) 
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:231) 
    at com.sun.enterprise.v3.services.impl.ContainerMapper$AdapterCallable.call(ContainerMapper.java:317) 
    at com.sun.enterprise.v3.services.impl.ContainerMapper.service(ContainerMapper.java:195) 
    at com.sun.grizzly.http.ProcessorTask.invokeAdapter(ProcessorTask.java:860) 
    at com.sun.grizzly.http.ProcessorTask.doProcess(ProcessorTask.java:757) 
    at com.sun.grizzly.http.ProcessorTask.process(ProcessorTask.java:1056) 
    at com.sun.grizzly.http.DefaultProtocolFilter.execute(DefaultProtocolFilter.java:229) 
    at com.sun.grizzly.DefaultProtocolChain.executeProtocolFilter(DefaultProtocolChain.java:137) 
    at com.sun.grizzly.DefaultProtocolChain.execute(DefaultProtocolChain.java:104) 
    at com.sun.grizzly.DefaultProtocolChain.execute(DefaultProtocolChain.java:90) 
    at com.sun.grizzly.http.HttpProtocolChain.execute(HttpProtocolChain.java:79) 
    at com.sun.grizzly.ProtocolChainContextTask.doCall(ProtocolChainContextTask.java:54) 
    at com.sun.grizzly.SelectionKeyContextTask.call(SelectionKeyContextTask.java:59) 
    at com.sun.grizzly.ContextTask.run(ContextTask.java:71) 
    at com.sun.grizzly.util.AbstractThreadPool$Worker.doWork(AbstractThreadPool.java:532) 
    at com.sun.grizzly.util.AbstractThreadPool$Worker.run(AbstractThreadPool.java:513) 
    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) 
    ... 31 more 
Caused by: java.lang.NullPointerException 
    at beans.LoginBean.login(LoginBean.java:49) 
    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 com.sun.el.parser.AstValue.invoke(AstValue.java:254) 
    at com.sun.el.MethodExpressionImpl.invoke(MethodExpressionImpl.java:302) 
    at com.sun.faces.facelets.el.TagMethodExpression.invoke(TagMethodExpression.java:105) 
    at javax.faces.component.MethodBindingMethodExpressionAdapter.invoke(MethodBindingMethodExpressionAdapter.java:88) 
    ... 32 more

내 컨트롤러 클래스입니다

package ejb; 

import java.util.List; 

import javax.ejb.LocalBean; 
import javax.ejb.Stateful; 
import javax.persistence.EntityManager; 
import javax.persistence.NoResultException; 
import javax.persistence.Query; 

import javax.persistence.PersistenceContext; 

import model.Group; 
import model.User; 
import model.UserGroup; 

@Stateful 
@LocalBean 
public class UserGroupDaoBean { 
    @PersistenceContext(unitName = "myPU") 
    private EntityManager entityManager; 

    public UserGroupDaoBean() { 

    } 

    public UserGroup createNewUserGroup(int groupId, String username) { 

     UserGroup newUserGrp = new UserGroup(); 

     User myUsr; 
     myUsr = entityManager.find(User.class, username); 
     newUserGrp.setUser(myUsr); 

     Group myGrp; 
     myGrp = entityManager.find(Group.class, groupId); 
     newUserGrp.setGroup(myGrp); 

     saveNewUsrGrp(newUserGrp); 
     return newUserGrp; 
    } 

    private void saveNewUsrGrp(UserGroup usrGrp) { 
     entityManager.persist(usrGrp); 
     entityManager.flush(); 
    } 

    public boolean checkUsertoGroup(String username, int groupId) { 

     Group chkGrp; 
     chkGrp = entityManager.find(Group.class, groupId); 

     User chkUsr; 
     chkUsr = entityManager.find(User.class, username); 

     if (chkGrp != null) { 

      if (chkUsr != null) { 

       try { 
        entityManager.createNamedQuery("findGroupsbyUser") 
          .setParameter("username", chkUsr) 
          .setParameter("groupId", chkGrp).getSingleResult(); 
        System.out.println("UserGroup already exists"); 
        return false; 
       } catch (NoResultException e) { 
        return true; 
       } 

      } 
      System.out.println("User doesn't exist"); 
      return false; 
     } 
     System.out.println("Group doesn't exist"); 

     return false; 

    } 

    public void deleteUserGroup(UserGroup userGroup) { 
     userGroup = entityManager.merge(userGroup); 
     entityManager.remove(userGroup); 
    } 

    public UserGroup update(UserGroup myUserGroup) { 
     return entityManager.merge(myUserGroup); 
    } 

    @SuppressWarnings("unchecked") 
    public List<UserGroup> getAllUserGroups() { 

     try { 
      Query query = entityManager.createNamedQuery("findAllUserGroup"); 
      List<UserGroup> result = (List<UserGroup>) query.getResultList(); 
      return result; 

     } catch (NoResultException e) { 
      System.out.println("No Result found"); 
      return null; 
     } 
    } 

    public boolean validateGroup(String username, int groupId) { 

     try { 
      UserGroup myGroupId = (UserGroup) entityManager 
        .createNamedQuery("findGroup") 
        .setParameter("username", username) 
        .setParameter("groupId", groupId).getSingleResult(); 

      if (myGroupId != null) { 
       System.out.println("This user is admin!!!"); 
       return true; 
      } 

     } catch (NoResultException e) { 
      return false; 
     } 

     System.out.println("This user is not admin"); 
     return false; 
    } 
}

다음은 스택 추적을 읽어 내 엔티티 사용자 그룹

package model; 

import java.io.Serializable; 
import javax.persistence.*; 


/** 
* The persistent class for the UserGroup database table. 
* 
*/ 
@NamedQueries({ 

    @NamedQuery(name = "findGroupsbyUser", query = "Select ug.group from UserGroup ug where ug.user=:username AND ug.group=:groupId"), 

    @NamedQuery(name = "findAllUserGroup", query="Select ug from UserGroup ug"), 

    @NamedQuery(name = "findAdminGroupId", query = "Select ug from UserGroup ug where ug.user=:username AND ug.group=:groupId"), 


}) 
@Entity 
@Table(name="usergroup") 
public class UserGroup implements Serializable { 
    private static final long serialVersionUID = 1L; 

    @Id 
    @GeneratedValue(strategy = GenerationType.IDENTITY) 
    @Column(name="RowId") 
    private int rowId; 

    //bi-directional many-to-one association to Group 
    @ManyToOne 
    @JoinColumn(name="groupId") 
    private Group group; 

    //bi-directional many-to-one association to User 
    @ManyToOne 
    @JoinColumn(name="username") 
    private User user; 

    public UserGroup() { 
    } 

    public int getRowId() { 
     return this.rowId; 
    } 

    public void setRowId(int rowId) { 
     this.rowId = rowId; 
    } 

    public Group getGroup() { 
     return this.group; 
    } 

    public void setGroup(Group group) { 
     this.group = group; 
    } 

    public User getUser() { 
     return this.user; 
    } 

    public void setUser(User user) { 
     this.user = user; 
    } 

}

출처

2013-03-28 sushantpandey

경우 : NPE가 LoginBean.java의 라인 49에 슬로우됩니다.

EJB 주석이 없기 때문에 uGBD이 null입니다. 당신은 당신이 주입하는 EJB와의 각 앞에 @EJB 주석을 사용해야합니다

@EJB 
private UserDaoBean uDB; 
@EJB 
private UserGroupDaoBean uGDB; 
...

출처

2013-03-28 23:32:01 perissf

아를! 정말 나 바보 야! 고마워요. 많이 해결 됐어요. – sushantpandey

얻기 javax.faces.FacesException : java.lang.NullPointerException이

답변

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