SchedulerLeakProtector

import java.lang.ref.WeakReference;
import java.util.concurrent.*;
import java.util.function.Consumer;

public class SchedulerLeakProtector {

    public static <T> ScheduledFuture<?> scheduleAtFixedRate(ScheduledExecutorService scheduler, T target, Consumer<T> consumer, long initialDelay, long period, TimeUnit timeUnit) {
        CompletableFuture<ScheduledFuture<?>> scheduledFutureFuture = new CompletableFuture<>();
        LeakProtectedRunnable<T> runnable = new LeakProtectedRunnable<>(target, consumer, scheduledFutureFuture);
        ScheduledFuture<?> scheduledFuture = scheduler.scheduleAtFixedRate(runnable, initialDelay, period, timeUnit);
        scheduledFutureFuture.complete(scheduledFuture);
        return scheduledFuture;
    }

    private static final class LeakProtectedRunnable<T> implements Runnable {

        private final WeakReference<T> targetReference;
        private final Consumer<T> consumer;
        private final CompletableFuture<ScheduledFuture<?>> scheduledFutureFuture;

        LeakProtectedRunnable(T target, Consumer<T> consumer, CompletableFuture<ScheduledFuture<?>> scheduledFutureFuture) {
            this.targetReference = new WeakReference<>(target);
            this.consumer = consumer;
            this.scheduledFutureFuture = scheduledFutureFuture;
        }

        @Override
        public void run() {
            T target = targetReference.get();
            if (target != null) {
                // target object still strong referenced
                consumer.accept(target);
                return;
            }

            // target object became unreachable lets cancel scheduled task
            try {
                scheduledFutureFuture.get().cancel(false);
            } catch (Exception e) {
                throw new IllegalStateException(e);
            }
        }

    }

}

Sometimes you need to do something periodical work under object until it strongly referenced. But adding new scheduled task to executor leads to creation new strong reference, so object has no chanses to became unreachable. This utility class protect object from leak strong reference through ScheduledExecutorService.