invokeAndWait for JavaFX

最新推荐文章于 2025-09-05 16:34:31 发布

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最新推荐文章于 2025-09-05 16:34:31 发布

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文章标签： java raspberry pi

本文介绍了一种在JavaFX中模拟SwingUtilities.invokeAndWait功能的方法，通过使用Platform.runLater结合锁和条件变量实现了同步等待任务完成的功能。

http://www.guigarage.com/2013/01/invokeandwait-for-javafx/

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Swing offers the two methods SwingUtilities.invokeAndWait(…) and SwingUtilities.invokeLater(…) to execute a Runnable object on Swings event dispatching thread. You can read more about this methods here.

As I currently know JavaFX provides only Platform.runLater(…) that is the equivalent of SwingUtilities.invokeLater(…). A “runAndWait” method doesn’t exist at the moment. While developing some DataFX stuff and my first Raspberry Pi demo I needed this feature in JavaFX. So I created a runAndWait method that will hopefully be part of DataFX in some future. Until then you can use this code in your project:

import java.util.concurrent.ExecutionException;
import java.util.concurrent.locks.Condition;
import java.util.concurrent.locks.Lock;
import java.util.concurrent.locks.ReentrantLock;
 
import javafx.application.Platform;
 
/**
 * General JavaFX utilities
 *
 * @author hendrikebbers
 *
 */
public class FXUtilities {
 
    /**
     * Simple helper class.
     *
     * @author hendrikebbers
     *
     */
    private static class ThrowableWrapper {
        Throwable t;
    }
 
    /**
     * Invokes a Runnable in JFX Thread and waits while it's finished. Like
     * SwingUtilities.invokeAndWait does for EDT.
     *
     * @param run
     *            The Runnable that has to be called on JFX thread.
     * @throws InterruptedException
     *             f the execution is interrupted.
     * @throws ExecutionException
     *             If a exception is occurred in the run method of the Runnable
     */
    public static void runAndWait(final Runnable run)
            throws InterruptedException, ExecutionException {
        if (Platform.isFxApplicationThread()) {
            try {
                run.run();
            } catch (Exception e) {
                throw new ExecutionException(e);
            }
        } else {
            final Lock lock = new ReentrantLock();
            final Condition condition = lock.newCondition();
            final ThrowableWrapper throwableWrapper = new ThrowableWrapper();
            lock.lock();
            try {
                Platform.runLater(new Runnable() {
 
                    @Override
                    public void run() {
                        lock.lock();
                        try {
                            run.run();
                        } catch (Throwable e) {
                            throwableWrapper.t = e;
                        } finally {
                            try {
                                condition.signal();
                            } finally {
                                lock.unlock();
                            }
                        }
                    }
                });
                condition.await();
                if (throwableWrapper.t != null) {
                    throw new ExecutionException(throwableWrapper.t);
                }
            } finally {
                lock.unlock();
            }
        }
    }
}