How can i validate the type and size of a file during an upload in the jvx framework

How can i validate the type and size of a file when i am using the ProjXUtil.uploadFile function?

ProjXUtil.uploadFile(this, new Var(mdbDokumente, "FILENAME"), new Var(mdbDokumente, "FILE_"));

More parameters in over the function uploadFile for filetype and size are not possible to set

I don't use a utility, instead with following snippet:

UploadButton butUpload = new UploadButton();
butUpload.eventAction().addListener(this, "doUpload");


public void doUpload(UIActionEvent pEvent) throws Throwable
{
    IFileHandle fhandle = ((UploadButton)pEvent.getSource()).getFileHandle();
        
    if (book.getSelectedRow() >= 0)
    {
        String sFormat = FileUtil.getExtension(fhandle.getFileName().toLowerCase());

        if ("png".equals(sFormat) || "jpg".equals(sFormat))
        {
            InputStream stream = fhandle.getInputStream();

            
            ...


            book.setValue("IMAGE", stream.toByteArray());
        }
    }
}