xml数字签名 封装模式

public static void generateXMLDigitalSignature(String originalXmlFilePath, String destnSignedXmlFilePath)
     throws NoSuchAlgorithmException, InvalidAlgorithmParameterException, KeyException, FileNotFoundException, SAXException, IOException, ParserConfigurationException, MarshalException, XMLSignatureException, TransformerException, KeyStoreException, CertificateException, UnrecoverableEntryException, InstantiationException, IllegalAccessException, ClassNotFoundException
   {
     XMLSignatureFactory fac = XMLSignatureFactory.getInstance("DOM");
     Reference ref = fac.newReference
       ("#DataObjectId", fac.newDigestMethod(DigestMethod.SHA1, null),
        Collections.singletonList
         (fac.newTransform
          (Transform.ENVELOPED, (TransformParameterSpec) null)),
           null, null);
     DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance(); 
     dbf.setNamespaceAware(true);
     org.w3c.dom.Document doc = dbf.newDocumentBuilder().parse(new FileInputStream(originalXmlFilePath));
     org.w3c.dom.Element documentElement = doc.getDocumentElement();
     DOMStructure domStructure = new DOMStructure(documentElement);
     XMLObject newXMLObject = fac.newXMLObject(Collections.singletonList(domStructure), "DataObjectId", null, null);
     SignedInfo si = fac.newSignedInfo
       (fac.newCanonicalizationMethod(
        CanonicalizationMethod.INCLUSIVE, (C14NMethodParameterSpec)null), fac.newSignatureMethod(SignatureMethod.RSA_SHA1, null), 
       Collections.singletonList(ref));

     KeyStore ks = KeyStore.getInstance(KeyStore.getDefaultType());
     ks.load(new FileInputStream(keyStoreSignFilePath), keyStoreSignFilePassword.toCharArray());
     KeyStore.PrivateKeyEntry keyEntry = (KeyStore.PrivateKeyEntry)ks.getEntry(privateKey, new KeyStore.PasswordProtection(privateKeyPassword.toCharArray()));
     X509Certificate cert = (X509Certificate)keyEntry.getCertificate();
  /*   //直接读取证书
     CertificateFactory cf = CertificateFactory.getInstance("X.509");
     FileInputStream fis = new FileInputStream(new File("e:/gdmlhenc.cer"));
     X509Certificate cert = (X509Certificate) cf.generateCertificate(fis);
     fis.close();