Primefaces download file from datatable

Question

I have this weird issue with File Download option not being called from the XHTML. I am very new to JSF, so it might be something basic that I am screwing up, but any help would be appreciated.

This is my XHTML

<p>Files List</p>
<h:form prependId="false">
    <p:dataTable value="#{pc_ArchiveFiles.archiveFiles}" var="fs"
        paginator="true" rows="5"
        paginatorTemplate="{CurrentPageReport}  {FirstPageLink} {PreviousPageLink} {PageLinks} {NextPageLink} {LastPageLink} {RowsPerPageDropdown}"
        rowsPerPageTemplate="5,10,15">
        <f:facet name="header">  
            Client Files  
        </f:facet>
        <p:column>
            <f:facet name="header">
                File Name
            </f:facet>
             <h:outputText value="#{fs.fileName}" /> 
        </p:column>
        <p:column>
            <f:facet name="header">
                File Size
            </f:facet>
            <h:outputText value="#{fs.fileSizeInKB}" />
        </p:column>
        <p:column>
            <f:facet name="header">
               Download File
            </f:facet>
            <p:commandLink id="downloadLink" value="Download" ajax="false">  
                    <p:fileDownload value="#{pc_ArchiveFiles.downloadPDF}" />
            </p:commandLink> 
        </p:column>
    </p:dataTable>
</h:form>

This is the backing bean

@ManagedBean(value = "pc_ArchiveFiles")
@RequestScoped
public class ArchiveFiles extends PageCodeBase {
private static final Logger logger = LoggerFactory
        .getLogger(ArchiveFiles.class);
 @Value("${archive.location}")
private String repository;
public List<ArchiveFile> getArchiveFiles() {


    Map<String, String> params = FacesContext.getCurrentInstance()
            .getExternalContext().getRequestParameterMap();
    subCategory = params.get("categoryName");

    // Build request object
    ArchiveFilesRequest request = new ArchiveFilesRequest();
    request.setCaseWorkerId(SecurityUtil.getLoggedInUser().getLoggedUserId());
    request.setClientId(getSelectedConsumer().getConsumerId());
    request.setCategoryName(subCategory);
    ArchiveFilesResponse response = archiveService.getArchiveFiles(request);
    if((response.getResponseType() == ResponseType.SUCCESS || response.getResponseType() == ResponseType.WARNING) && response.getFileCount() > 0) { // There is at least one file
        archiveFiles = new ArrayList<ArchiveFile>();
        archiveFiles.addAll(response.getFileSet());
        return archiveFiles;
    } else {
        return Collections.<ArchiveFile> emptyList();
    }
}


 public void downloadPDF() throws IOException {

        FacesContext facesContext = FacesContext.getCurrentInstance();
        ExternalContext externalContext = facesContext.getExternalContext();
        HttpServletResponse response = (HttpServletResponse) externalContext.getResponse();

        facesContext.responseComplete();
    }

}

When I click on download, I want the downloadPDF() called. But it seems to be calling getArchiveFiles() method again instead of downloadPDF(). I have changed p:CommandLink to the below code, but it still does not call the right method. On top of it I have to pass in the filename parameter as well if I get this working.

<h:commandLink id="downloadLink" value="Download PDF" target="_blank" action="#{pc_ArchiveFiles.downloadPDF}" />

Answer 1

value attribute for p:fileDownload should be an instance of StreamedContent. check in the documentation here on page 174 it should be something like code below:

     <p:commandButton id="downloadLink" value="Download" ajax="false" onclick="PrimeFaces.monitorDownload(start, stop)"   
        icon="ui-icon-arrowthichk-s">  
    <p:fileDownload value="#{fileDownloadController.file}" />  
</p:commandButton>  



 private StreamedContent file;  
 public StreamedContent getFile() {  
        return file;  
    }    
public void setFile(StreamedContent file){
 InputStream stream = ((ServletContext)FacesContext.getCurrentInstance().getExternalContext().getContext()).getResourceAsStream("/images/optimusprime.jpg");  
        file = new DefaultStreamedContent(stream, "image/jpg", "downloaded_optimus.jpg");  
}

If you want downloadPDF() listener fired from h:commandLink you should use actionListener instead of action attribute:

<h:commandLink id="downloadLink" value="Download PDF" target="_blank" actionListener="#{pc_ArchiveFiles.downloadPDF}" />