/**
 * Validates a given XML document against a given schema.
 *
 * @param xmlFilename filename with XML document.
 * @param schema XSD schema to validate with.
 *
 * @throws AppEngineConfigException for malformed XML, or IO errors
 */
public static void validateXml(String xmlFilename, File schema) {
  File xml = new File(xmlFilename);
  if (!xml.exists()) {
    throw new AppEngineConfigException("Xml file: " + xml.getPath() + " does not exist.");
  }
  if (!schema.exists()) {
    throw new AppEngineConfigException("Schema file: " + schema.getPath() + " does not exist.");
  }
  try {
    validateXmlContent(Files.toString(xml, StandardCharsets.UTF_8), schema);
  } catch (IOException ex) {
    throw new AppEngineConfigException(
        "IO error validating " + xmlFilename + " against " + schema.getPath(), ex);
  }
}
 

public void updateWebXml(List<String> services, String webXmlPath)
        throws ParserConfigurationException, SAXException, IOException,
        TransformerFactoryConfigurationError, TransformerException {
  boolean saveRequired;

  String spc = " ";
  String delimiter = "\n";

  DocumentBuilderFactory docFactory = DocumentBuilderFactory.newInstance();
  DocumentBuilder docBuilder = docFactory.newDocumentBuilder();
  Document document = docBuilder.parse(webXmlPath);

  Node systemServiceServletNode = findSystemServiceServlet(document);
  if (systemServiceServletNode == null) {
    getLog().info("Not a valid web.xml document");
    return;
  }
  if (isElementAndNamed(systemServiceServletNode, WEB_APP)) {
    systemServiceServletNode = insertSystemServiceServlet(document,
            systemServiceServletNode, spc, delimiter);
    saveRequired = true;
  }

  saveRequired = updateSystemServiceServletParam(document,
          systemServiceServletNode, services);
  String generatedWebInf = outputDirectory + "/WEB-INF";      
  new File(generatedWebInf).mkdirs();
  saveFile(document, generatedWebInf + "/web.xml");
  Files.copy(
          new File(new File(webXmlPath).getParentFile(), "appengine-web.xml"),
          new File(generatedWebInf, "appengine-web.xml"));
}
 

public void updateWebXml(List<String> services, String webXmlPath)
    throws ParserConfigurationException, SAXException, IOException,
    TransformerFactoryConfigurationError, TransformerException {
  boolean saveRequired;

  String spc = " ";
  String delimiter = "\n";

  DocumentBuilderFactory docFactory = DocumentBuilderFactory.newInstance();
  DocumentBuilder docBuilder = docFactory.newDocumentBuilder();
  Document document = docBuilder.parse(webXmlPath);

  Node systemServiceServletNode = findSystemServiceServlet(document);
  if (systemServiceServletNode == null) {
    getLog().info("Not a valid web.xml document");
    return;
  }
  if (isElementAndNamed(systemServiceServletNode, WEB_APP)) {
    systemServiceServletNode = insertSystemServiceServlet(document,
        systemServiceServletNode, spc, delimiter);
    saveRequired = true;
  }

  saveRequired = updateSystemServiceServletParam(document,
      systemServiceServletNode, services);
  String generatedWebInf = outputDirectory + "/WEB-INF";
  new File(generatedWebInf).mkdirs();
  saveFile(document, generatedWebInf + "/web.xml");
  Files.copy(
      new File(new File(webXmlPath).getParentFile(), "appengine-web.xml"),
      new File(generatedWebInf, "appengine-web.xml"));
}