Javafx将舞台/场景保存到文件中

Question

I have tried several ways including jaxb and serializing. Both didn't really work. The node s in the stage/scene include Label , BarChart and CodeArea from richTextFX. for the serializing method, i get java.io.NotSerializableException: javafx.scene.chart.BarChart . Is there a way to save a scene/stage to a file such as xml (not FXML just saying)? then, I can restore the scene/stage even if i closed the application. many thanks.

Answer 1

As per James_D comment you should save the data from your UI elements not the elements themselves'cos you have them already coded, right?)

A short snippet of the way I did it:

public class SaveRestoreDemo extends Application {

    public static void main(String[] args) {
        Application.launch(args);
    }

    @Override
    public void start(Stage primaryStage) {
        primaryStage.setTitle("Save/restore demo");
        Group root = new Group();
        Scene scene = new Scene(root, 600, 250, Color.WHITE);

        BorderPane borderPane = new BorderPane();
        borderPane.prefHeightProperty().bind(scene.heightProperty());
        borderPane.prefWidthProperty().bind(scene.widthProperty());

        VBox box = new VBox(10);
        TextArea area = new TextArea();
        area.setId("textArea");

        TextField field = new TextField();
        field.setId("field");

        box.getChildren().addAll(area, field);

        borderPane.setTop(getMainMenuContainer(box.getChildren()));
        borderPane.setCenter(box);
        root.getChildren().add(borderPane);
        primaryStage.setScene(scene);
        primaryStage.show();
    }

    private VBox getMainMenuContainer(ObservableList<Node> children) {
        VBox topContainer = new VBox();
        MenuBar mainMenu = new MenuBar();
        topContainer.getChildren().add(mainMenu);
        Menu menu = new Menu("Menu");

        MenuItem load = new MenuItem("Load");
        load.setOnAction(e -> load(children));

        MenuItem save = new MenuItem("Save");
        save.setOnAction(e -> save(children));

        menu.getItems().addAll(save, load);

        mainMenu.getMenus().add(menu);
        return topContainer;
    }

    private void load(ObservableList<Node> children) {
        FileChooser fileChooser = new FileChooser();
        fileChooser.setTitle("Load file");
        File file = fileChooser.showOpenDialog(new Stage());
        if (file != null) {
            try {
                Values values = new Gson().fromJson(org.apache.commons.io.FileUtils.readFileToString(file, StandardCharsets.UTF_8), Values.class);
                children.stream().filter(child -> child.getId() != null)
                        .forEach(child -> {
                            if (child instanceof TextField) {
                                TextField field = (TextField) child;
                                field.setText(values.getFieldText());
                            } else if (child instanceof TextArea) {
                                TextArea area = (TextArea) child;
                                area.setText(values.getAreaText());
                            }
                        });
            } catch (IOException e) {
                // handle properly
            }
        }
    }

    private void save(ObservableList<Node> children) {
        FileChooser fileChooser = new FileChooser();
        fileChooser.setTitle("Save file");
        File file = fileChooser.showSaveDialog(new Stage());
        if (file != null) {
            Values values = new Values();
            children.stream().filter(child -> child.getId() != null)
                    .forEach(child -> {
                        if (child instanceof TextField) {
                            TextField field = (TextField) child;
                            values.setFieldText(field.getText());
                        } else if (child instanceof TextArea) {
                            TextArea area = (TextArea) child;
                            values.setAreaText(area.getText());
                        }
                    });

            try {
                org.apache.commons.io.FileUtils.write(file, new Gson().toJson(values), StandardCharsets.UTF_8);
            } catch (IOException e) {
                // handle properly
            }
        }
    }

    private static class Values {
        private String areaText;
        private String fieldText;

        public String getAreaText() {
            return areaText;
        }

        public void setAreaText(String areaText) {
            this.areaText = areaText;
        }

        public void setFieldText(String fieldText) {
            this.fieldText = fieldText;
        }

        public String getFieldText() {

            return fieldText;
        }
    }
}

Basically, I just loop through children of main container, gather values from them and then save to Json using Gson and Apache Commons. This example is very simple, for more complicated saving\\loading you can use id of the nodes. For example, you can keep a list or map of ids and then use them as an identifiers while saving and loading.