How interact between PublishSubject and PublishProcessor to simulate deliveries? - java-8

Question

How interact between PublishSubject and PublishProcessor to simulate deliveries?
I have this problem:
I have a list of Orders
Receive the orders filter by temp hot, cook the order,
Place the order on the hot shelf, after that a courier will deliver the orders every 3 seconds.
If the shelf is full discard the orders in the shelf.
Hot shelf -> Size: 10
I tried use PublishSubject to send to a PublishProcessor that will be the hot shelf
but that does not work?
Any idea about how to achieve that?
I do not have to much experience with reactive programming.
import io.reactivex.rxjava3.core.BackpressureOverflowStrategy;
import io.reactivex.rxjava3.processors.PublishProcessor;
import io.reactivex.rxjava3.schedulers.Schedulers;
import io.reactivex.rxjava3.subjects.PublishSubject;
import java.util.List;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.atomic.AtomicInteger;
public class App{
public static void main( String[] args ){
ReadJson read = new ReadJson();
List<Order> list = read.cargarArchivoJson("orders.json");
PublishSubject<Order> subjectOrder = PublishSubject.create();
PublishProcessor<Order> hotShelf = PublishProcessor.create();
AtomicInteger hotSize = new AtomicInteger(0);
subjectOrder.observeOn(Schedulers.computation())
.filter(r -> r.getTemp().equals("hot"))
.subscribe(
s -> {
hotSize.set(hotSize.get() + 1);
System.out.println("Sent to hot Shelf, Size: " + hotSize.get());
hotShelf.onNext(s);
},
Throwable::printStackTrace,
() -> System.out.println("--- Processed all Hot Temperature Orders")
);
hotShelf.onBackpressureBuffer(10, () ->{ System.out.println("dropping the oldest .. "); }, BackpressureOverflowStrategy.DROP_OLDEST)
.observeOn(Schedulers.computation())
.subscribe(s -> {
System.out.println("Waiting for the courier..");
TimeUnit.SECONDS.sleep(3);
hotSize.set(hotSize.get() - 1);
System.out.println("Hot Order delivered, Size on hot Shelf: " + hotSize.get());
}, Throwable::printStackTrace);
for(int i = 0; i < list.size(); i++){
subjectOrder.onNext(list.get(i));
}
}
}
the output is:
Sent to hot Shelf, Size: 1
Sent to hot Shelf, Size: 2
Sent to hot Shelf, Size: 3
Sent to hot Shelf, Size: 4
Sent to hot Shelf, Size: 5
Sent to hot Shelf, Size: 6
Waiting for the courier..
Sent to hot Shelf, Size: 7
Sent to hot Shelf, Size: 8
Sent to hot Shelf, Size: 9
..
It finished when the loop to iterate the list ends and it didn't deliver a single order.
Udpate:
Now is working but the problem it does not discard after 10, it does after a large amount, how would be the best way to discard a Order because using a atomic inteteger is not the best way of do this also beacuse I want to know the id of the discarded order.
Is there a way to end the program once the hotShelf ends? to avoid a while loop or a Thread.sleep().
public static void main( String[] args ){
ReadJson read = new ReadJson();
List<Order> list = read.cargarArchivoJson("orders.json");
Subject<Order> subjectOrder = (Order)PublishSubject.create().toSerialized();
PublishProcessor<Order> hotShelf = PublishProcessor.create();
AtomicInteger hotSize = new AtomicInteger(0);
subjectOrder.observeOn(Schedulers.computation())
.filter(r -> r.getTemp().equals("hot"))
.subscribe(
s -> {
hotSize.set(hotSize.get() + 1);
System.out.println("Sent to hot Shelf, Size: " + hotSize.get());
hotShelf.onNext(s);
},
Throwable::printStackTrace,
() -> System.out.println("--- Processed all Hot Temperature Orders")
);
hotShelf.onBackpressureBuffer(10, () ->{ System.out.println("dropping the oldest .. "); hotSize.set(hotSize.get() -1); }, BackpressureOverflowStrategy.DROP_OLDEST)
.observeOn(Schedulers.computation())
.subscribe(s -> {
System.out.println("Waiting for the courier..");
TimeUnit.SECONDS.sleep(3);
hotSize.set(hotSize.get() - 1);
System.out.println("Hot Order delivered, Size on hot Shelf: " + hotSize.get());
}, Throwable::printStackTrace);
for(int i = 0; i < list.size(); i++){
subjectOrder.onNext(list.get(i));
}
subjectOrder.onComplete();
boolean flag;
while(!hotShelf.hasComplete()){
flag = false; // just for test to avoid an error on a empty while
}
}