Primefaces 5 FileUploadEvent, not all files are uploading

Question

I am developing a page in Primefaces 5 and using p:fileUpload tag in advanced mode to upload multiple files.

I have got the file upload working fine, but while I was testing I noticed that sometimes not all the files were actualy uploaded. Ex: I upload 6 files and only 4 files actually upload.

As I was looking through the trace log I also noticed that the method only ran 4 times (previous example), leading me to believe that only 4 ajax requests out of the expected 6 where made.

In Page

<h:form enctype="multipart/form-data">
     <p:fileUpload   fileUploadListener="#{fileUploaderBean.uploadFile}"
                     mode="advanced"
                     dragDropSupport="true"
                     multiple="true"
                     update="filesId"
                     sizeLimit="100000"
                     ajax="true"/>
<p:outputPanel id="filesId">
     <p:dataTable    value="#{fileUploaderBean.uploadedFiles}" 
                     var="uploadedFile" 
                     id="filesTable" 
                     action="#{fileUploaderBean.testAjax}">
           <p:column headerText="Uploaded File/s">
                 <h:outputText value="#{uploadedFile}" />
           </p:column>
     </p:dataTable>
</p:outputPanel>

Bean

private List<UploadedFile> filesList = Collections.synchronizedList(new ArrayList<UploadedFile>());
private List<String> uploadedFiles = Collections.synchronizedList(new ArrayList<String>());

public void uploadFile (FileUploadEvent fileUploadEvent) throws IOException 
{
    LOGGER.info("Running uploadFile fileUploadEvent={}", fileUploadEvent);

    saveFileToStagingFolder(fileUploadEvent.getFile().getFileName(), fileUploadEvent.getFile().getInputstream());
    uploadedFiles.add(fileUploadEvent.getFile().getFileName());

    LOGGER.info("uploadFile process complete");
}

Answer 1

Add this to web.xml

<filter>
    <filter-name>PrimeFaces FileUpload Filter</filter-name>
    <filter-class>org.primefaces.webapp.filter.FileUploadFilter</filter-class>
</filter>

I only had this in my web.xml had forgoten to add the filter itself

<filter-mapping>
    <filter-name>PrimeFaces FileUpload Filter</filter-name>
    <servlet-name>faces</servlet-name>
    <dispatcher>FORWARD</dispatcher>
</filter-mapping>

Looks like the FileUploader will work without it but not very well at all. Would think a configuraton error like that would of log something to indicate where the problem was.