Getting the HTML of a page.

Question

I wish I could retrieve as a string the HTML content of a page displayed by a webEngine.
I know this code works:
webEngine.getPage().getHtml(webEngine.getMainFrame());
But getPage() and getMainFrame() are not public.
What is the "official" way to get the HTML content of a page as a string?

Answer 1

import javafx.application.Application;
import javafx.beans.value.ChangeListener;
import javafx.beans.value.ObservableValue;
import javafx.scene.Scene;
import javafx.scene.control.Label;
import javafx.scene.layout.VBox;
import javafx.scene.web.WebView;
import javafx.stage.Stage;
import org.w3c.dom.Document;
import org.w3c.dom.Node;
import org.w3c.dom.ls.DOMImplementationLS;
import org.w3c.dom.ls.LSSerializer;
import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.ParserConfigurationException;
// Getting the HTML of a page. "Getting the HTML of a page"
public class DocumentPrinter extends Application {
  public static final String CONTENT =
      "<dl>\n" +
      "<dt>Coffee</dt>\n" +
      "<dd>- black hot drink</dd>\n" +
      "<dt>Milk</dt>\n" +
      "<dd>- white cold drink</dd>\n" +
      "</dl>";
  public static void main(String[] args) { launch(args); }
  @Override public void start(Stage primaryStage) {
    // create view with some content in it.
    final WebView view = new WebView();
    view.getEngine().loadContent(CONTENT);
    view.setPrefSize(200, 100);
    // hold a log the view's document.
    final Label documentLabel = new Label();
    // write the document to the document label
    view.getEngine().documentProperty().addListener(new ChangeListener<Document>() {
      @Override public void changed(ObservableValue<? extends Document> observableValue, Document oldValue, Document webViewDocument) {
        try {
          Node originalRoot = webViewDocument.getDocumentElement();
          // copying the document is necessary in this case because the serializer
          // we are using is not realized by the webview document implementation.
          // if you used a different serialization library, perhaps the copy step would not be required.
          // http://stackoverflow.com/questions/5226852/cloning-dom-document-object
          DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
          DocumentBuilder db = dbf.newDocumentBuilder();
          Document copiedDocument = db.newDocument();
          Node copiedRoot = copiedDocument.importNode(originalRoot, true);
          copiedDocument.appendChild(copiedRoot);
          // weird dom api for serialization.
          // http://stackoverflow.com/questions/1219596/how-to-i-output-org-w3c-dom-element-to-string-format-in-java
          DOMImplementationLS domImplLS = (DOMImplementationLS) copiedDocument.getImplementation();
          LSSerializer serializer = domImplLS.createLSSerializer();
          // update the document label with serialized document.
          documentLabel.setText(serializer.writeToString(copiedRoot));
        } catch (ParserConfigurationException e) {
          e.printStackTrace();
    // layout the scene.
    final VBox layout = new VBox(10);
    layout.setStyle("-fx-padding: 10; -fx-background-color: cornsilk");
    layout.getChildren().addAll(
      new Title("Web View"),          view,
      new Title("Original Content"),  new Label(CONTENT),
      new Title("Rendered Document"), documentLabel
    primaryStage.setScene(new Scene(layout, 450, 450));
    primaryStage.show();
  class Title extends Label {
    Title(String titleString) { super(titleString); setStyle("-fx-font-weight: bold;"); }
}