同時運行javafx和swing應用程序

Question

我正在使用Java中的Webcam Capture API訪問我的網絡攝像頭。 Webcam Capture API是基於Swing構建的，我知道，但是我想將Webcam Swing類與JavaFX類結合使用。 JavaFX類在屏幕上顯示一個矩形。 我的目標是：運行JavaFX類，該類在屏幕上顯示矩形。 在某個時候（例如，單擊鼠標），我想啟動網絡攝像頭。 設置網絡攝像頭以查看屏幕，然后應對矩形圖像進行某些操作。

JavaFX類：

public class JavaFXDisplay extends Application {

    @Override
    public void start(Stage primaryStage) {
        WebcamCapture wc = new WebcamCapture();

        StackPane root = new StackPane();

        Rectangle rectangle = new Rectangle();
        rectangle.setWidth(500);
        rectangle.setHeight(500);

        Scene scene = new Scene(root, 1000, 1000);
        root.getChildren().addAll(rectangle);

        primaryStage.setScene(scene);
        primaryStage.show();

        scene.addEventFilter(MouseEvent.MOUSE_PRESSED, new EventHandler<MouseEvent>() {
            @Override
            public void handle(MouseEvent mouseEvent) {
                wc.doSomething();
            }
        });
   }

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

秋千課：

public class WebcamCapture extends JFrame implements Runnable, ThreadFactory {

    private static final long serialVersionUID = 6441489157408381878L;

    private Executor executor = Executors.newSingleThreadExecutor(this);

    private Webcam webcam = null;
    private WebcamPanel panel = null;
    private JTextArea textarea = null;

    public WebcamCapture() {
        super();

        setLayout(new FlowLayout());
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

        Dimension size = WebcamResolution.QVGA.getSize();

        webcam = Webcam.getWebcams().get(0);
        webcam.setViewSize(size);

        panel = new WebcamPanel(webcam);
        panel.setPreferredSize(size);

        textarea = new JTextArea();
        textarea.setEditable(false);
        textarea.setPreferredSize(size);

        add(panel);
        add(textarea);

        pack();
        setVisible(true);
    }

    public void doSomething() {
        executor.execute(this);
    }

    @Override
    public void run() {
        do {
            try {
                Thread.sleep(100);
            } catch (InterruptedException e) {
                e.printStackTrace();
            }

            BufferedImage image = null;

            if (webcam.isOpen()) {
                if ((image = webcam.getImage()) == null) {
                    continue;
                }

                doSomeStuff;
            }
        } while (true);
    }

    @Override
    public Thread newThread(Runnable r) {
        Thread t = new Thread(r, "example-runner");
        t.setDaemon(true);
        return t;
    }

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

但是我的JavaFX類沒有啟動/顯示。 我的代碼有什么問題？

Answer 1

我不熟悉您使用的網絡攝像頭API（因此，我不知道這是否是唯一的錯誤），但是您確實需要在AWT事件分配線程上創建Swing內容。 當前，您正在FX Application Thread上創建它。

您可以使用以下成語：

public class JavaFXDisplay extends Application {

    private WebcamCapture wc ;

    @Override
    public void init() throws Exception {
        super.init();
        FutureTask<WebcamCapture> launchWebcam = new FutureTask<>(WebcamCapture::new) ;
        SwingUtilities.invokeLater(launchWebcam);

        // block until webcam is started:
        wc = launchWebcam.get();
    }

    @Override
    public void start(Stage primaryStage) throws Exception {

        StackPane root = new StackPane();

        Rectangle rectangle = new Rectangle();
        rectangle.setWidth(500);
        rectangle.setHeight(500);

        Scene scene = new Scene(root, 1000, 1000);
        root.getChildren().addAll(rectangle);

        primaryStage.setScene(scene);
        primaryStage.show();

        scene.addEventFilter(MouseEvent.MOUSE_PRESSED, new EventHandler<MouseEvent>() {
            @Override
            public void handle(MouseEvent mouseEvent) {
                wc.doSomething();
            }
        });
   }

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

作為參考，這是僅JavaFX的網絡攝像頭查看器。 我在運行OS X Sierra（10.12.2）的MacBookPro上進行了測試，該顯示器帶有2011年的27“ Thunderbolt顯示屏和攝像頭。

import java.awt.Dimension;
import java.awt.image.BufferedImage;
import java.util.concurrent.ArrayBlockingQueue;
import java.util.concurrent.BlockingQueue;
import java.util.concurrent.Executor;
import java.util.concurrent.Executors;

import com.github.sarxos.webcam.Webcam;
import com.github.sarxos.webcam.WebcamResolution;

import javafx.animation.AnimationTimer;
import javafx.application.Application;
import javafx.embed.swing.SwingFXUtils;
import javafx.scene.Scene;
import javafx.scene.image.Image;
import javafx.scene.image.ImageView;
import javafx.scene.layout.StackPane;
import javafx.stage.Stage;

public class FXWebCamViewer extends Application {

    private BlockingQueue<Image> imageQueue = new ArrayBlockingQueue<>(5);

    private Executor exec = Executors.newCachedThreadPool(runnable -> {
        Thread t = new Thread(runnable);
        t.setDaemon(true);
        return t ;
    });

    private Webcam webcam;

    @Override
    public void init() {
        webcam = Webcam.getWebcams().get(0);
        Dimension viewSize = WebcamResolution.QVGA.getSize();
        webcam.setViewSize(viewSize);
        webcam.open();
    }

    @Override
    public void start(Stage primaryStage) {
        ImageView imageView = new ImageView();

        StackPane root = new StackPane(imageView);
        imageView.fitWidthProperty().bind(root.widthProperty());
        imageView.fitHeightProperty().bind(root.heightProperty());
        imageView.setPreserveRatio(true);

        AnimationTimer updateImage = new AnimationTimer() {
            @Override
            public void handle(long timestamp) {
                Image image = imageQueue.poll();
                if (image != null) {
                    imageView.setImage(image);
                }
            }
        };
        updateImage.start();

        exec.execute(this::generateImages);

        Scene scene = new Scene(root, 600, 600);
        primaryStage.setScene(scene);
        primaryStage.show();
    }

    private void generateImages() {
        while (! Thread.interrupted()) {
            try {
                if (webcam.isOpen() && webcam.isImageNew()) {
                    BufferedImage bimg = webcam.getImage();
                    if (bimg != null) {
                        imageQueue.put(SwingFXUtils.toFXImage(bimg, null));
                    }
                } else {
                    Thread.sleep(250);
                }
            } catch (InterruptedException e) {
                Thread.currentThread().interrupt();
            }
        }
    }

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