ExecutorService中的不确定任务 [英] Indefinite task in ExecutorService

问题描述

我有以下变量:

    private ExecutorService executor;
    private Task<Boolean> worker;

我有一个任务应该在另一个线程中执行，并且应该监视其状态:

I have a task that should be performed in another thread and the state of which should be monitored:

    public Worker<Boolean> updateTemplateBuffer() {
    worker = new Task<Boolean>() {
        @Override
        protected Boolean call() throws Exception {
               //task code
    };
    executor.execute(worker);
    return worker; 
}

任务已正确执行，但我无法跟踪任务是否结束.

The task is executed correctly, but I can’t track whether the task has ended or not.

方法executor.isTerminated()和executor.isShutdown()始终在调用时始终为false. 告诉我如何正确跟踪任务的状态(开始或完成)，因为我以前从未遇到过多线程编程.

Methods executor.isTerminated() and executor.isShutdown() always false anytime of a call. Tell me how to track the state of the task correctly (started or completed), because I had never encountered multi-threaded programming before.

推荐答案

接口，该接口具有 state 属性.您可以在 更改为SUCCEEDED，CANCELLED或FAILED.

Task implements the Worker interface which has the state property. You can listen to this property and react when the Worker.State changes to SUCCEEDED, CANCELLED, or FAILED.

Task<Boolean> task = ...;
task.stateProperty().addListener((obs, oldVal, newVal) -> {
    // Test newVal and do something as needed...
});

或者您可以收听 running 属性.

Or you could listen to the running property.

task.runningProperty().addListener((obs, oldVal, newVal) -> {
    if (!newVal) {
        // Do something...
    }
});

您还可以收听 WorkerStateEvent 上的> s.

You can also listen for WorkerStateEvents on the Task.

task.setOnSucceeded(event -> {});
task.setOnCancelled(event -> {});
task.setOnFailed(event -> {});

// or even something like
task.addEventHandler(WorkerStateEvent.ANY, event -> {
    // Test event type and do something as needed...
});

然后还有受保护的状态方法".

Then there's also the protected "state methods".

Task<Boolean> task = new Task<>() {

    @Override
    protected Boolean call() throws Exception {
        return false;
    }

    @Override protected void succeeded() {}
    @Override protected void cancelled() {}
    @Override protected void failed() {}

});

所有这些选项都会在 JavaFX Application Thread 上通知您.

All these options will notify you on the JavaFX Application Thread.

这篇关于ExecutorService中的不确定任务的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！