JavaFX - 等待任务完成

Question

我有一个JavaFX应用程序,它实例化几个Task对象.

目前,我的实现(见下文)调用行为runFactory(),它在Task对象下执行计算.与此并行,调用nextFunction().有没有办法让nextFunction() "等待"直到前一个任务完成？

我理解thread.join()等待运行的线程完成,但是使用GUI,由于事件调度线程,还有其他复杂的层.事实上,将thread.join()添加到下面的代码段末尾只会停止UI交互.

如果有任何建议如何使nextFunction等到它的先前函数,runFactory完成,我将非常感激.

谢谢,

// High-level class to run the Knuth-Morris-Pratt algorithm.
public class AlignmentFactory {
    public void perform() {
        KnuthMorrisPrattFactory factory = new KnuthMorrisPrattFactory();
        factory.runFactory();   // nextFunction invoked w/out runFactory finishing.
        // Code to run once runFactory() is complete.
        nextFunction()   // also invokes a Task.
        ...
    }
}

// Implementation of Knuth-Morris-Pratt given a list of words and a sub-string.
public class KnuthMorrisPratt {
   public void runFactory() throws InterruptedException {
       Thread thread = null;
       Task<Void> task = new Task<Void>() {

           @Override public Void call() throws InterruptedException {
           for (InputSequence seq: getSequences) {
                KnuthMorrisPratt kmp = new KnuthMorrisPratt(seq, substring);
                kmp.align();

            }
            return null; 
        }
    };
    thread = new Thread(task);
    thread.setDaemon(true);
    thread.start();
}

Answer 1

当您使用需要使用的任务setOnSucceeded并且可能setOnFailed在程序中创建逻辑流程时,我建议您还runFactory()返回任务而不是运行它:

// Implementation of Knuth-Morris-Pratt given a list of words and a sub-string.
public class KnuthMorrisPratt {
   public Task<Void> runFactory() throws InterruptedException {
       return new Task<Void>() {

       @Override public Void call() throws InterruptedException {
       for (InputSequence seq: getSequences) {
        KnuthMorrisPratt kmp = new KnuthMorrisPratt(seq, substring);
        kmp.align();

        }
        return null; 
    }
    };
}

// High-level class to run the Knuth-Morris-Pratt algorithm.
public class AlignmentFactory {
    public void perform() {
    KnuthMorrisPrattFactory factory = new KnuthMorrisPrattFactory();
    Task<Void> runFactoryTask = factory.runFactory();
    runFactoryTask.setOnSucceeded(new EventHandler<WorkerStateEvent>() {
        @Override
        public void handle(WorkerStateEvent t)
        {
            // Code to run once runFactory() is completed **successfully**
            nextFunction()   // also invokes a Task.
        }
    });

    runFactoryTask.setOnFailed(new EventHandler<WorkerStateEvent>() {
        @Override
        public void handle(WorkerStateEvent t)
        {
            // Code to run once runFactory() **fails**
        }
    });
    new Thread(runFactoryTask).start();
    }
}