我正在使用primfaces 5版本来显示我的数据库中的数据库中的图像，但不幸的是，而不是实际的图像＆＃34;图像＆＃34;正在写入列，这是我的xhtml文件。 我有一个带有StreamedContent属性的对象列表，我需要在组件中显示它。 我抛出没有结果的showcase primefaces
<p:dataTable id="dta" value="#{UtilisateurComponent.listUtilisateurs()}" var="current" rows="15" paginator="true" paginatorPosition="bottom" rowKey="current.iduser">
<p:column>
<f:facet name="header">
<h:outputText value="id User" />
</f:facet>
<h:outputText value="#{current.iuser}" />
</p:column>
<p:column >
<f:facet name="header">
<h:outputText value="Photo" />
</f:facet>
<p:graphicImage value="#{UtilisateurComponent.content}" height="100" width="150">
<f:param name="id" value="#{current.iduser}" />
</p:graphicImage>
</p:column>
</p:dataTable>
这是我的托管bean：
enter code here
@Scope("session")
@Component("UtilisateurComponent")
public class UtilisateurComponentImpl implements UtilisateurComponent {
private Utilisateur utilisateur;
byte[] f;
private UploadedFile file;
private StreamedContent content;
@Autowired
private UtilisateurDAO utilisateurDAO;
@Autowired
private UtilisateurService utilisateurService;
public StreamedContent getContent() {
FacesContext context = FacesContext.getCurrentInstance();
if (context.getCurrentPhaseId() == PhaseId.RENDER_RESPONSE) {
return new DefaultStreamedContent();
}
else{
String imageId = context.getExternalContext().getRequestParameterMap().get("id");
Utilisateur u = utilisateurDAO.findUtilisateurByIduser(Integer.parseInt(imageId));
return new DefaultStreamedContent(new ByteArrayInputStream(u.getPhoto())); //the line that throw the Error
}
}
public void setContent(StreamedContent content) {
this.content = content;
}
@PostConstruct
public void init() {
//initialize the data here
this.utilisateur = new Utilisateur();
}
public UploadedFile getFile() {
return file;
}
public void setFile(UploadedFile file) {
this.file = file;
}
@Transactional
public String saveUtilisateurTest(Utilisateur utilisateur) {
try{
utilisateur.setPhoto(getFile().getContents());
utilisateurService.saveUtilisateur(utilisateur);
file=null;
}
catch(Exception ex){
ex.printStackTrace();
}
return "/jsf/utilisateur/listUtilisateurs.xhtml";
}
f = new byte[event.getFile().getContents().length];
System.arraycopy(event.getFile().getContents(),0,f,0,event.getFile().getContents().length);
FacesMessage message = new FacesMessage("Succesful", event.getFile().getFileName() + " is uploaded.");
FacesContext.getCurrentInstance().addMessage(null, message);
}
}
根据我的堆栈跟踪，
Grave: Error in streaming dynamic resource. Error reading 'content' on type $Proxy16
juin 17, 2014 10:56:03 PM org.apache.catalina.core.StandardWrapperValve invoke
Grave: "Servlet.service()" pour la servlet Faces Servlet a généré une exception
java.io.IOException: javax.el.ELException: Error reading 'content' on type $Proxy16
at org.primefaces.application.PrimeResourceHandler.handleResourceRequest(PrimeResourceHandler.java:122)
at javax.faces.webapp.FacesServlet.service(FacesServlet.java:306)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:303)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
at org.primefaces.webapp.filter.FileUploadFilter.doFilter(FileUploadFilter.java:98)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
at org.springframework.orm.jpa.support.OpenEntityManagerInViewFilter.doFilterInternal(OpenEntityManagerInViewFilter.java:113)
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:76)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:220)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:122)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:501)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:170)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:98)
at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:950)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:116)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:408)
at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1040)
at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:607)
at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:315)
at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
at java.lang.Thread.run(Unknown Source)
Caused by: javax.el.ELException: Error reading 'content' on type $Proxy16
at javax.el.BeanELResolver.getValue(BeanELResolver.java:110)
at javax.el.CompositeELResolver.getValue(CompositeELResolver.java:67)
at com.sun.faces.el.FacesCompositeELResolver.getValue(FacesCompositeELResolver.java:71)
at com.sun.el.parser.AstValue.getValue(AstValue.java:116)
at com.sun.el.parser.AstValue.getValue(AstValue.java:163)
at com.sun.el.ValueExpressionImpl.getValue(ValueExpressionImpl.java:219)
at org.primefaces.application.PrimeResourceHandler.handleResourceRequest(PrimeResourceHandler.java:85)
... 27 more
Caused by: java.lang.NullPointerException
at java.io.ByteArrayInputStream.<init>(Unknown Source)
at com.gestion.projet.web.jsf.UtilisateurComponentImpl.getContent(UtilisateurComponentImpl.java:119)
at sun.reflect.GeneratedMethodAccessor38.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
该行（UtilisateurComponentImpl.java:119）在managedbean方法上发表了评论
StreamedContent getMyContent()
答案 0 :(得分：0)
return new DefaultStreamedContent(new ByteArrayInputStream(u.getPhoto()));
在上面的行中，你是null，问题是你没有把他从DataBase带回来，或者你没有在bean中接收到imageId。
你可以这样做
<p:graphicImage value="#{UtilisateurComponent.getContent(current.iduser)}" height="100" width="150"/>
在您的功能中，只需获取您的用户ID
即可public StreamedContent getContent(Integer userId){...}
希望这会有所帮助
答案 1 :(得分：-1)
问题在于传递了param，你有一个包含多行的dataTable然后你发送具有相同id的params。