下面是FileUploadDialog构件的一般用法。

首先创建托管Bean：

@ManagedBean(scope=ManagedBeanScope.REQUEST) 
public class FileUploadDialogBean { 
  
  @Accessible
  private UIFileUploadDialog fileUpload;

  public void processFileUpload(HttpServletRequest request, HttpServletResponse response) throws IOException {
        ServletFileUpload upload = new ServletFileUpload();
        InputStream stream = null;
        BufferedInputStream bis = null;
        BufferedOutputStream bos = null;
        try {
            if (ServletFileUpload.isMultipartContent(request)) {
                if (fileUpload.getFileSizeMax() != null) {
                    upload.setSizeMax(fileUpload.getFileSizeMax());
                }
                FileItemIterator iter = upload.getItemIterator(request);
                while (iter.hasNext()) {
                    FileItemStream item = iter.next();
                    stream = item.openStream();
                    if (!item.isFormField()) {
                        String filename = new File(item.getName()).getName();
                        bis = new BufferedInputStream(stream);
                        bos = new BufferedOutputStream(new FileOutputStream(new File("/tmp/" + filename)));
                        Streams.copy(bis, bos, true);
                    }
                }
                response.getWriter().write("{success:true}");
            }
        } catch (FileUploadException e) {
            response.getWriter().write(String.format("{success:false,message:'%s'}", e.getMessage()));
        } finally{
            if(stream != null){
                try{
                    stream.close();
                }catch(Exception e){}
            }
            if(bis != null){
                try{
                    bis.close();
                }catch(Exception e){}
            }
            if(bos != null){
                try{
                    bos.close();
                }catch(Exception e){}
            }
        }
  } 

  ...... 

}

下面是页面代码：

<w:form>
<w:fileUploadDialog id="fileUpload" fileSizeMax="1048576" binding="#{FileUploadDialogBean.fileUpload}" jsvar="fileUploadDialog" processUpload="#{FileUploadDialogBean.processFileUpload}"></w:fileUploadDialog>
<br /> 
<w:button value="Show File Upload Dialog" onclick="fileUploadDialog.show();return false;" /> <br /> 
</w:form>