java - Java Task ProgressProperty错误？

我有几个任务，它们的progressProperty始终为-1。根据我的经验，-1通常意味着一些东西，但是我在文档中找不到任何有关它的信息。有人知道这意味着什么吗？还是我设定进度的错误？

为了使这个问题更多地涉及我的个人问题，您必须知道我将多个任务的progressProperty结合在一起，并使用doubleBinding将其绑定到进度栏。根据要求，这里有一些代码，为了使代码最小化，我删除了一些东西，例如导入声明，main方法并标记了重要部分。

public class X extends Application implements EventHandler<ActionEvent> {

    private Task<Void> taskRun;
    private Y y;
    private ExecutorService exec; // <-- Executor Service
    private Stage dialog;
    private Stage window;
    //Interface inter;
    Scene scene;

    private ProgressBar progress; // <-- Progress Bar

    @Override
    public void start(Stage primaryStage) {

        y = new Y();

        window = primaryStage;
        exec = Executors.newCachedThreadPool(); // <-- Executor Service

        progress = new ProgressBar(0.0); // <-- Progress Bar
        VBox vb = new VBox();
        vb.getChildren().add(progress);
        scene = new Scene(vb);

        window.setScene(scene);
        window.show();
        run();
    }

    private DoubleBinding progressBinding = null; // <-- Double binding

    private void run() {
            taskRun = new Task<Void>() {
                @Override
                public void run() {
                    try {
                        ConverterManager();
                    } catch (InterruptedException ex) {
                        Logger.getLogger(X.class.getName()).log(Level.SEVERE, null, ex);
                    }

                }

                @Override
                protected Void call() throws Exception {
                    throw new UnsupportedOperationException("Not supported yet.");
                }
            };
            // I need to use the progressProperty of this task first
            progressBinding = taskRun.progressProperty().multiply(1);
            // Binding doubleBinding to progressBar
            progress.progressProperty().bind(progressBinding);
            exec.execute(taskRun);
    }

    private void ConverterManager() throws InterruptedException {

        progressBinding = null; // <-- Reset doubleBinding

        int anz = 5;
        for (int i = 0; i < anz; i++) {
            Task<Void> mt = new Task<Void>() {
                @Override
                public void run() {
                    try {
                        // I use another class and have to update
                        // progress there, I do so with a BiConsumer
                        y.setProgressUpdate(this::updateProgress);
                        // Here I call a Method from the other class
                        // the String parameter is, because I use
                        // a reflection there
                        y.startZ("Z");
                    } catch (Exception ex) {
                        Logger.getLogger(X.class.getName()).log(Level.SEVERE, null, ex);
                    }
                }

                @Override
                protected Void call() throws Exception {
                    throw new UnsupportedOperationException("Not supported yet.");
                }
            };
            // Here I combine the progress of the different ProgressProperties
            // Also, I notized that mt.ProgressProperty.get() is -1 for all tasks
            DoubleBinding scaledProgress = mt.progressProperty().divide(anz);
            if (progressBinding == null) {
                progressBinding = scaledProgress;
            } else {
                // Adding the scaled down progress of the Task to the
                // doubleBinding that is connected to the progressBar
                progressBinding = progressBinding.add(scaledProgress);
            }

            exec.execute(mt);
        };
    }

    @Override
    public void handle(ActionEvent event) {
        throw new UnsupportedOperationException("Not supported yet.");
    }

}

这是Y班

public class Y {
    private BiConsumer<Integer, Integer> progressUpdate;

    public void setProgressUpdate(BiConsumer<Integer, Integer> progressUpdate) {
        this.progressUpdate = progressUpdate;
    }

    void startZ(String className) throws Exception {
        Class cls = Class.forName("stackoverflow." + className);
        Object obj = cls.newInstance();

        Class[] noParams = new Class[0];

        Class[] progressParams = new Class[1];
        progressParams[0] = BiConsumer.class;

        Method bindProgress = cls.getDeclaredMethod("setProgressUpdate", progressParams);
        bindProgress.invoke(obj, progressUpdate);

        Method method = cls.getDeclaredMethod("start", noParams);
        method.invoke(obj);
    }
}

这是Z类：

public class Z
{
    private BiConsumer<Integer, Integer> progressUpdate;

    public void setProgressUpdate(BiConsumer<Integer, Integer> progressUpdate) {
        this.progressUpdate = progressUpdate ;
    }

    public void start() {
            int gesamt = 1000;
            for (int i = 1; i < gesamt; i++) {
                if (progressUpdate != null)
                    progressUpdate.accept(i, gesamt);
            }
    }
}

最佳答案

看看java doc


  值-1表示无法确定当前进度
  （即不确定）。此属性可能会或可能不会更改
  从默认值-1开始，具体取决于特定的Worker
  实施。