Primefaces Multiple FileUpload doesn't show files nor triggers the handleFileUpload - file-upload

Question

I'm searching since one week and couldn't find a proper solution for my problem. So I'm asking the experts here.
I'm trying to implement a page with FileUpload to upload and show the images after upload on same page.
my problem is, if I set my ManagedBean to #RequestScope, the handleFileUpload function will not be triggered.
If I set it to #ViewScope, the function will be triggered but the error "Error in streaming dynamic resource." is shown.
here are my files:
web.xml
<filter>
<filter-name>PrimeFaces FileUpload Filter</filter-name>
<filter-class>org.primefaces.webapp.filter.FileUploadFilter</filter-class>
<init-param>
<param-name>thresholdSize</param-name>
<param-value>2097152</param-value>
</init-param>
<init-param>
<param-name>uploadDirectory</param-name>
<param-value>E:/uploadedImages</param-value>
</init-param>
PrimeFaces FileUpload Filter
Faces Servlet
Bean
#ManagedBean
#RequestScoped
public class ImageManager implements Serializable {
private final static int MAX_UPLOADED_FILES = 5;
private final static String UPLOADED_FILES_PATH = "E:/uploadedImages";
private final Map<UUID, UploadedFile> uploadedFiles = new HashMap<>();
public List<String> getListImages() {
final List<String> result = new ArrayList<>();
for (final UUID uuid : uploadedFiles.keySet())
result.add(uuid.toString());
return result;
}
public StreamedContent getImage() {
final ExternalContext externalContext = FacesContext.getCurrentInstance().getExternalContext();
final String imageId = (String) externalContext.getRequestMap().get("imageId");
if (imageId != null) {
final UUID imageIndex = UUID.fromString(imageId);
return new DefaultStreamedContent(new ByteArrayInputStream(uploadedFiles.get(imageIndex).getContents()), "image/jpg");
}
return null;
}
public void handleFileUpload(FileUploadEvent event) {
if (uploadedFiles.size() < MAX_UPLOADED_FILES) {
final UploadedFile uploadedFile = event.getFile();
if (uploadedFile != null) {
uploadedFiles.put(UUID.randomUUID(), uploadedFile);
}
}
}
}
xhtml
<p:fileUpload fileUploadListener="#{imageManager.handleFileUpload}"
mode="advanced"
multiple="true"
sizeLimit="2097152"
allowTypes="/(\.|\/)(gif|jpe?g|png)$/"
uploadLabel="Hochladen"
auto="false"
cancelLabel="Abbrechen"
invalidFileMessage="Die ausgewählte Datei ist kein zugelassene Bilddatei"
invalidSizeMessage="Die maximale Bildgröße ist 2MB"
label="Datei Auswählen"
update="imageList"
/>
<ui:repeat value="#{imageManager.listImages}" var="imageId" id="imageList">
<h:outputText value="#{imageId}" />
<p:graphicImage value="#{imageManager.image}">
<f:param id="imageId" name="imageId" value="#{imageId}" />
</p:graphicImage>
</ui:repeat>

Answer 1

#Daniel, blieve me. I've searched many days before I post my question here. But I have resolved the Problem by myself.
here is the solution in case that somebody has the same problem:
#Controller
#Scope(WebApplicationContext.SCOPE_REQUEST)
public class ImageManager implements Serializable {
private final static int MAX_UPLOADED_FILES = 5;
private final static String UPLOADED_FILES_PATH = "E:/uploadedImages";
private final static Map<UUID, UploadedFile> uploadedFiles = new HashMap<>();
private final static List<String> listImages = new ArrayList<>();
private StreamedContent image;
private static StreamedContent defaultImage = null;
static {
try {
defaultImage = new DefaultStreamedContent(new FileInputStream(new File("E:\\uploadedImages\\t.jpg")), "image/jpg");
}
catch (FileNotFoundException e) {
e.printStackTrace();
}
}
public List<String> getListImages() {
return listImages;
}
public StreamedContent getImage() {
final ExternalContext externalContext = FacesContext.getCurrentInstance().getExternalContext();
final String imageId = (String) externalContext.getRequestParameterMap().get("imageId");
if (imageId != null) {
final UUID imageIndex = UUID.fromString(imageId);
image = new DefaultStreamedContent(new ByteArrayInputStream(uploadedFiles.get(imageIndex).getContents()), "image/jpg");
return image;
}
return defaultImage;
}
public void handleFileUpload(FileUploadEvent event) {
if (uploadedFiles.size() < MAX_UPLOADED_FILES) {
final UploadedFile uploadedFile = event.getFile();
if (uploadedFile != null) {
final UUID uuid = UUID.randomUUID();
uploadedFiles.put(uuid, uploadedFile);
listImages.add(uuid.toString());
}
}
}
public void setImage(StreamedContent image) {
this.image = image;
}
}