UploadedFile - 空指針異常

Question

我想基於示例中給出的示例file upload Primeup 3.0的組件。我還添加了commons-fileupload-1.2.2.jar和commons-io-2.0.1.jar以及primefaces-3.1.jar文件。

我運行上傳程序我得到一個java.lang.NullPointerException任何人都可以請幫我解決這個問題，我已經廣泛搜索了互聯網，找不到一個有效的解決方案。

我正在使用NetBeans 7.2.1和GlassFish進行部署。

我的代碼： XHTML：

<h:form id="frm" enctype="multipart/form-data"> 
     <table> 
      <tr><td><div style="height:300px;"><img src="images/adcar.jpg" style="top:0px;"/> 
        </div> 
        </td> 
       <td> 
        <h:form id="img" enctype="multipart/form-data"> 
<div style=" -moz-border-radius:15px; border:1px solid; width:600px; border-color:#930303;"> 
    <br></br> 
     <p:panel style="border:none;"> 
     <p:messages></p:messages> 
     </p:panel> 
     <h:panelGrid columns="2"> 
      <h:outputText value="Nom Projet :"/> 
      <h:inputText id="Nom" value="#{ajoutprjt.nomProjet}" /> 
      <h:outputText value="Ref Projet :"></h:outputText><h:inputText value="#{ajoutprjt.idProjet}" /> 
      <h:outputText value="Date de Début :"></h:outputText><h:inputText value="#{ajoutprjt.dateDeb}" /> 
      <h:outputText value="Date de Fin :"></h:outputText><h:inputText value="#{ajoutprjt.dateFin}" /> 
      <h:outputText value="Chef :"></h:outputText> 
      <h:selectOneMenu value="#{ajoutprjt.idChef}"> 
       <f:selectItem itemValue="#{null}" itemLabel="-- select one --" /> 
       <f:selectItems value="#{ajoutprjt.tdata}" var="cmd" 
              itemValue="#{cmd.id}" itemLabel="#{cmd.id} #{cmd.nom} #{cmd.prenom}" /> 
      </h:selectOneMenu> 
      Documents : <p:fileUpload value="#{ajoutprjt.file}" id="fileupload" mode="simple"></p:fileUpload> 
      <h:outputText></h:outputText><p:panel style="border: none;"><p:commandButton value="Ajouter" action="#{ajoutprjt.ajoutP}" ajax="false"></p:commandButton><p:commandButton value="Annuler" action="#{ajoutprjt.annuleraj}" ajax="false"></p:commandButton></p:panel> 
     </h:panelGrid> 
     </div> 
        </h:form> 
    </td></tr> </table> 
     </h:form>[/code] 

我的豆：

package beans; 

import com.persistence.Compte; 
import com.persistence.Projets; 
import com.persistence.geoUtil; 
import java.io.File; 
import java.io.Serializable; 
import java.util.ArrayList; 
import java.util.List; 
import java.util.logging.Logger; 
import javax.faces.application.FacesMessage; 
import javax.faces.bean.ManagedBean; 
import javax.faces.bean.RequestScoped; 
import javax.faces.context.FacesContext; 
import javax.faces.model.DataModel; 
import javax.faces.model.ListDataModel; 
import org.hibernate.Query; 
import org.hibernate.Session; 
import org.hibernate.Transaction; 
import org.primefaces.model.UploadedFile; 
/** 
* 
* @author SA 
*/ 
@ManagedBean 
@RequestScoped 
public class ajoutprjt implements Serializable{ 

    private String idpro; 
    private String IdProjet; 
    private String NomProjet; 
    private String DateDeb; 
    private String DateFin; 
    private String nomimg; 
    private UploadedFile file; 
    private String IdChef; 
    private DataModel<Compte> tdata ; 

     public ajoutprjt(){ 

         } 
     // getters et Setters 

    ... 

    public UploadedFile getFile() { 
     System.out.println("Je suis sous GetFile: "); 
     return file; 
    } 

    public void setFile(UploadedFile file) { 
     System.out.println("je Suis Sous SetFile : "); 
     this.file = file; 
    } 


    public void ajoutP(){ 
    // String p=Integer.toString(puis); 
    System.out.println("Ajout Projet de ref : " +IdProjet); 
    System.out.println("Ajout Projet de Idchef est : " +IdChef); 
    System.out.println("file a ajouter e : " +this.getFile().getSize()); 
    if(IdProjet.equals("")==false && NomProjet.equals("")==false && DateDeb.equals("")==false && DateFin.equals("")==false && IdChef.equals("")==false){ 

      try{ 
     Session se=geoUtil.getSessionFactory().getCurrentSession(); 
     Transaction tr=se.beginTransaction(); 
     Query q = se.createQuery("SELECT p from Projets p where IdProjet = :rf"); 
      q.setParameter("rf", IdProjet);  
      List<Object[]> list = (List<Object[]>) q.list(); 
      if(list.size() == 0){ 

     Projets p =new Projets(); 

     p.setNomProjet(NomProjet); 
     p.setIdProjet(IdProjet); 
     p.setDateDeb(DateDeb); 
     p.setDateFin(DateFin); 
     p.setIdChef(IdChef); 
     // UploadedFile file = event.getFile(); 
      if(this.getFile()!= null) { 
       String fileName = file.getFileName(); 
       byte[] fileBytes = file.getContents(); 
       p.setNomimg(fileName); 
       p.setImg(fileBytes);} 
      else{ 
         p.setNomimg("Pas de fichier"); 
         String s = "a"; 
         byte[] a = s.getBytes();  
         p.setImg(a); 
         } 
      se.persist(p); 
      tr.commit(); 

     context.addMessage(null,new FacesMessage(FacesMessage.SEVERITY_INFO,"Projet ajouté avec succes","Compte chef ajouté avec succes")); 
    this.setNomProjet(""); 
     this.setIdProjet(""); 
     this.setDateDeb(""); 
     this.setDateFin(""); 
     this.setIdChef(""); 

      }else{ 
       context.addMessage(null,new FacesMessage(FacesMessage.SEVERITY_ERROR,"Attention:Projet déjas existe","Attention")); 
      } 
      } 
      catch(Exception e1){ 
       e1.printStackTrace(); 
     context.addMessage(null,new FacesMessage(FacesMessage.SEVERITY_ERROR,"Attention:Erreur d'insertion","Attention")); 
      } 
      } 
     else{ 
     context.addMessage(null,new FacesMessage(FacesMessage.SEVERITY_WARN,"Attention Tous les champs doivent etre remplis!!","Attention")); 
     } 

    } 
} 

這是我的web.xml文件：

<?xml version="1.0" encoding="UTF-8"?> 
<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>javax.faces.PROJECT_STAGE</param-name> 
     <param-value>Development</param-value> 
    </context-param> 
    <context-param> 
     <param-name>primefaces.THEME</param-name> 
     <param-value>aristo</param-value> 
    </context-param> 
    <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>Faces Servlet</servlet-name> 
     <url-pattern>*.xhtml</url-pattern> 
     <url-pattern>/faces/*</url-pattern> 
    </servlet-mapping> 
    <session-config> 
     <session-timeout> 
      30 
     </session-timeout> 
    </session-config> 
    <welcome-file-list> 
     <welcome-file>faces/auth.xhtml</welcome-file> 
    </welcome-file-list> 
    <resource-ref> 
     <description>Base de données pour app Ontologie 
Projet master Pro</description> 
     <res-ref-name>jdbc/gcn</res-ref-name> 
     <res-type>javax.sql.DataSource</res-type> 
     <res-auth>Container</res-auth> 
     <res-sharing-scope>Shareable</res-sharing-scope> 
    </resource-ref> 
     <filter> 
     <filter-name>PrimeFaces FileUpload Filter</filter-name> 
     <filter-class> 
       org.primefaces.webapp.filter.FileUploadFilter 
     </filter-class> 
     </filter> 
     <filter-mapping> 
      <filter-name>PrimeFaces FileUpload Filter</filter-name> 
      <servlet-name>Faces Servlet</servlet-name> 
       <dispatcher>FORWARD</dispatcher> 
     </filter-mapping> 
</web-app> 

任何幫助將不勝感激。 這裏是堆棧跟蹤：

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) 
    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: java.lang.NullPointerException 
    at beans.ajoutprjt.ajoutP(ajoutprjt.java:176) 
    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 

Answer 1

你似乎有一個很多東西在該頁面上。這裏是我將如何處理調試：

• 如果你還沒有這樣做，下載所有的依賴關係（如果你確實做過，那麼請仔細檢查你的工作）。 這裏是link/source依賴關係

• 使用來自PrimeFace網站這個例子只是創建一個單獨 fileuploadController和查看網頁，就像他們有什麼在這個link

• 嘗試使上述步驟首先工作，一旦你有這個工作，然後開始將這些元素緩慢地添加到您現有的cur租用JSF頁面和控制器，並根據您的需求進行更改（從頭開始，而不是您已經修改併發布在此頁面上的內容）。

只有一兩件事我注意到：

• 我看你有嵌套ENCTYPE =「多部分/表單數據」被空就是你有太多的這些起作用的因素，這也許一個在一個頁面中，你的控制器只能獲得其中一個，但這只是一個受過良好教育的觀察，你可能需要在經歷上面列出的所有問題/步驟之前進行調試和研究。

Answer 2

在XHTML頁面使用actionListener代替action像

<p:commandButton value="Ajouter" actionListener="#{ajoutprjt.ajoutP}" 
ajax="false"></p:commandButton> 

，並更改ManagedBean ajoutP()方法

public void ajoutP(FileUploadEvent event){ 

     OutputStream out=null; 
     InputStream fileContent=null; 
     try{ 
      UploadedFile uploadedFile= event.getFile(); 
      out= new FileOutputStream(new 
          File("D:/")+uploadedFile.getFileName()); 
      fileContent= uploadedFile.getInputstream(); 
      int read=0; 
      final byte[] bytes= new byte[1024]; 
      while((read= fileContent.read(bytes))!=-1){ 
       out.write(bytes,0,read); 
      } 
     } 
     catch(FileNotFoundException fnfe){ 

     } 
     catch(IOException ioex){ 

     } 
} 

Answer 3

我不明白你如何使用這個方法的「ActionListener的」「ajoutP」像遵循「的ActionListener =」＃{} ajoutprjt.ajoutP「讓你在方法的參數」 ajoutP（FileUploadEvent事件）「。生成以下錯誤«javax.el.MethodNotFoundException»