java - JavaFX indeterminate progress bar while doing a process

Question

I am trying to insert to my database's one table but this process takes some minutes.

I would like to have a indeterminate progress bar while my application is trying to insert. In order to have progress bar, I want to use JavaFX but I don't know how to implement it that it just has be shown until the end of inserting in to the database process.

Answer 1

JavaFX Tasks are probably the way to go. They provide a way to execute long-running tasks in the background without freezing the user interface.

Here's an example of something you might try:

package Demo;

import javafx.application.Application;
import javafx.concurrent.Task;
import javafx.concurrent.WorkerStateEvent;
import javafx.event.ActionEvent;
import javafx.event.EventHandler;
import javafx.geometry.Insets;
import javafx.scene.Scene;
import javafx.scene.control.Button;
import javafx.scene.control.Label;
import javafx.scene.control.ProgressBar;
import javafx.scene.layout.VBox;
import javafx.stage.Stage;
import javafx.stage.StageStyle;

public class BackgroundWorkerDemo extends Application {

    private final static String CNTR_LBL_STR = "Counter: ";
    private int counter;

    Label counterLabel;
    Button counterButton;
    Button taskButton;

    @Override
    public void start(Stage primaryStage) {
        counter = 0;
        counterLabel = new Label(CNTR_LBL_STR + counter);
        counterButton = new Button("Increment Counter");
        counterButton.setOnAction(new EventHandler<ActionEvent>() {
            @Override
            public void handle(ActionEvent e) {
                counter++;
                counterLabel.setText(CNTR_LBL_STR + counter);
            }
        });
        taskButton = new Button("Long Running Task");
        taskButton.setOnAction(new EventHandler<ActionEvent>() {
            @Override
            public void handle(ActionEvent e) {
               runTask();
            }
        });

        VBox mainPane = new VBox();
        mainPane.setPadding(new Insets(10));
        mainPane.setSpacing(5.0d);
        mainPane.getChildren().addAll(counterLabel, counterButton, taskButton);
        primaryStage.setScene(new Scene(mainPane));
        primaryStage.show();
    }

    private void runTask() {

        final double wndwWidth = 300.0d;
        Label updateLabel = new Label("Running tasks...");
        updateLabel.setPrefWidth(wndwWidth);
        ProgressBar progress = new ProgressBar();
        progress.setPrefWidth(wndwWidth);

        VBox updatePane = new VBox();
        updatePane.setPadding(new Insets(10));
        updatePane.setSpacing(5.0d);
        updatePane.getChildren().addAll(updateLabel, progress);

        Stage taskUpdateStage = new Stage(StageStyle.UTILITY);
        taskUpdateStage.setScene(new Scene(updatePane));
        taskUpdateStage.show();

        Task longTask = new Task<Void>() {
            @Override
            protected Void call() throws Exception {
                int max = 50;
                for (int i = 1; i <= max; i++) {
                    if (isCancelled()) {
                        break;
                    }
                    updateProgress(i, max);
                    updateMessage("Task part " + String.valueOf(i) + " complete");

                    Thread.sleep(100);
                }
                return null;
            }
        };

        longTask.setOnSucceeded(new EventHandler<WorkerStateEvent>() {
            @Override
            public void handle(WorkerStateEvent t) {
                taskUpdateStage.hide();
            }
        });
        progress.progressProperty().bind(longTask.progressProperty());
        updateLabel.textProperty().bind(longTask.messageProperty());

        taskUpdateStage.show();
        new Thread(longTask).start();
    }

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

}

This version will update the task completion if you know how many parts your task will have. If not, comment out the line in the line that updates progress and you will get an indeterminate progress bar.

Note that while the long task is running, you can still increment the counter. Also note that you can start multiple long-running tasks with this program. If that is not what you want, you'll need to fiddle with the UI controls a bit.