public void digitalSignatures(){
       KGPdfHummer hummer = null;
       FileInputStream cert = null;
       FileOutputStream fileOutputStream = null;
       try {
             cert = new FileInputStream("D:/tmp/sign.pfx");
             fileOutputStream = new FileOutputStream("D:/tmp/2.pdf");
             hummer = KGPdfHummer.createSignature("D:/tmp/1.pdf", null, true, fileOutputStream, new File("D:/tmp/"),true);
             hummer.setCertificate(cert, "123456", "123456");
             PdfSignature4KG pdfSignature4KG = new PdfSignature4KG( "d:/tmp/iSignature.key",1,"123456");
             pdfSignature4KG.setText("金格科技");

             hummer.setPdfSignature(pdfSignature4KG);
             hummer.doSignature();
       } catch (Exception e) {
             e.printStackTrace();
       } finally {
             close(cert);
             close(fileOutputStream);
             if(hummer != null) hummer.close();
       }
}