Question

我需要在非常慢的设备上模拟应用的行为。所以我想覆盖Schedulers.io（）只使用一个低优先级的线程。并且，如果可能的话，在将任务排入队列之前添加一些延迟。有没有想法如何全局一次，没有更改Schedules.io（）调用代码？

Answer 1

您可以通过Schedulers.from(Executor)打包单个线程执行程序，然后将生成的Scheduler包装为另一个：

ExecutorService exec = Executors.newSingleThreadExecutor();
final Scheduler sch = Schedulers.from(exec);
final long delayMillis = 1000;

Scheduler newScheduler = new Scheduler() {
    @Override public Worker createWorker() {
        return new NewWorker(sch.createWorker());
    }

    class NewWorker extends Scheduler.Worker {
        final Worker actual;

        NewWorker(Worker actual) {
            this.actual = actual;
        }

        @Override public void unsubscribe() {
            actual.unsubscribe();
        }

        @Override public boolean isUnsubscribed() {
           return actual.isUnsubscribed();
        }

        @Override public Subscription schedule(Action0 action) {
            return actual.schedule(action, delayMillis, TimeUnit.MILLISECONDS);
        }

        @Override public Subscription schedule(Action0 action, long delayTime,
               TimeUnit unit) {
            return actual.schedule(action, delayTime, unit);
        }
    }
};

RxJavaHooks.setOnIOScheduler(original -> newScheduler);

Observable.just(1)
.observeOn(Schedulers.io())
.toBlocking()
.subscribe(System.out::println);

完成后，不要忘记关闭ExecutorService并重置挂钩：

exec.shutdown();
RxJavaHooks.setOnIOScheduler(null);

如何覆盖Schedulers.io（）？

1 个答案: