pdf.js显示合同签名问题

@RequestMapping(value = {"/showPdf.do", "showPdf"})
public String showPdf(ModelMap modelMap, HttpServletRequest request) throws Exception {
    log.info("---------------showPdf start---------------");
    HashMap<String, Object> hashMap = this.getHashMap(request);
    String pdfId = (String) hashMap.get("pdf_id");
    modelMap.put("pdf_id", pdfId);
    log.info("---------------showPdf end pdf_id:{}---------------", pdfId);
    return "manager/viewer";
}

<script>
    DEFAULT_URL = 'view_pdf?pdf_id=${pdf_id}';
</script>

var parent = Annotation.prototype;
Util.inherit(WidgetAnnotation, Annotation, {
isViewable: function WidgetAnnotation_isViewable() {
  // if (this.data.fieldType === 'Sig') {
  //   warn('unimplemented annotation type: Widget signature');
  //   return false;
  // }

  return parent.isViewable.call(this);
}
});