jnativehook无法找到如何触发关键事件

Question

我一直在试用jnativehook库和提供的示例，但我仍然无法触发关键方法发布。

package hookexample;

import java.awt.EventQueue;
import java.awt.Toolkit;
import java.awt.event.WindowEvent;
import java.awt.event.WindowListener;
import java.util.ArrayList;
import java.util.List;
import java.util.concurrent.AbstractExecutorService;
import java.util.concurrent.TimeUnit;
import javax.swing.JFrame;
import javax.swing.JOptionPane;
import javax.swing.SwingUtilities;
import javax.swing.WindowConstants;
import org.jnativehook.GlobalScreen;
import org.jnativehook.NativeHookException;
import org.jnativehook.keyboard.NativeKeyEvent;
import org.jnativehook.keyboard.NativeKeyListener;

public class NativeHookDemo extends JFrame implements NativeKeyListener, WindowListener {
    public NativeHookDemo() {
        // Set the event dispatcher to a swing safe executor service.
        GlobalScreen.getInstance().setEventDispatcher(new SwingExecutorService());

        setTitle("JNativeHook Swing Example");
        setSize(300, 150);
        setDefaultCloseOperation(WindowConstants.DISPOSE_ON_CLOSE);
        addWindowListener(this);
        setVisible(true);
    }

    public void windowOpened(WindowEvent e) {
        //Initialze native hook.
        try {
            GlobalScreen.registerNativeHook();
        }
        catch (NativeHookException ex) {
            System.err.println("There was a problem registering the native hook.");
            System.err.println(ex.getMessage());
            ex.printStackTrace();

            System.exit(1);
        }

        GlobalScreen.getInstance().addNativeKeyListener(this);
    }

    public void windowClosed(WindowEvent e) {
        //Clean up the native hook.
        GlobalScreen.unregisterNativeHook();
        System.runFinalization();
        System.exit(0);
    }

    public void windowClosing(WindowEvent e) { /* Unimplemented */ }
    public void windowIconified(WindowEvent e) { /* Unimplemented */ }
    public void windowDeiconified(WindowEvent e) { /* Unimplemented */ }
    public void windowActivated(WindowEvent e) { /* Unimplemented */ }
    public void windowDeactivated(WindowEvent e) { /* Unimplemented */ }

    public void nativeKeyReleased(NativeKeyEvent e) {
        System.out.println("Key released!");
        if (e.getKeyCode() == NativeKeyEvent.VC_SPACE) {
            JOptionPane.showMessageDialog(null, "This will run on Swing's Event Dispatch Thread.");
        }
    }

    public void nativeKeyPressed(NativeKeyEvent e) { /* Unimplemented */ }
    public void nativeKeyTyped(NativeKeyEvent e) { /* Unimplemented */ }

    public static void main(String[] args) {
         SwingUtilities.invokeLater(new Runnable() {
            public void run() {
                new SwingExample();
            }
        });
    }

    private class SwingExecutorService extends AbstractExecutorService {
        private EventQueue queue;

        public SwingExecutorService() {
            queue = Toolkit.getDefaultToolkit().getSystemEventQueue();
        }

        public void shutdown() {
            queue = null;
        }

        public List<Runnable> shutdownNow() {
            return new ArrayList<Runnable>(0);
        }

        public boolean isShutdown() {
            return queue == null;
        }

        public boolean isTerminated() {
            return queue == null;
        }

        public boolean awaitTermination(long timeout, TimeUnit unit) throws InterruptedException {
            return true;
        }

        public void execute(Runnable r) {
            EventQueue.invokeLater(r);
        }
    }
}

我只是简单地复制了https://github.com/kwhat/jnativehook/wiki/Usage上的示例，将类名和包名一起更改，并在nativeKeyReleased（）中的console命令中插入了一个System print。添加了库（JNativeHook v1.2.0-RC3）。当我运行代码时，它确实在控制台中显示鼠标和键事件的日志，但nativeKeyReleased（）从不触发。我错过了什么吗？