Why isn't my condition for adding an order to a queue passing?

Question about the task

Restaurant (part 20)

Java Multithreading, Level 9, Lesson 15

Under discussion

I'm adding an order to a queue in the update method as requested. What reason would there be for it not passing?

Fix a bug: a tablet sends its orders to all known chefs.
Expected behavior: a tablet sends its orders to a queue, and an available cook takes orders from the queue.

There are two ways to implement this functionality:
1) Each tablet stores a reference to the queue and pushes new orders to it.
2) A tablet pushes its orders to the Observer, which stores a reference to the queue. The Observer puts the order into the queue.

We'll take the second option.
1. In the root of the project, create an OrderManager class that will be an Observer for the tablets.
2. In the OrderManager class, create a LinkedBlockingQueue<Order> orderQueue field. Add to it all orders passed to the update method.
3. The Cook class is now NOT an Observer.
4. In the Cook class, create a void startCookingOrder(Order order) method. Move the update method's logic into this method.
5. Remove the update method from the Cook class.
6. In the main method, arrange an Observer-Observable relationship in view of the changes above.

Requirements:

The OrderManager class should support the Observer interface.
Orders sent to the OrderManager must be added to the orderQueue queue.
The Cook class should not support the Observer interface.
The Cook class must have a public void startCookingOrder(Order order) method.
The update method should be removed from the Cook class.

package com.codegym.task.task27.task2712; import com.codegym.task.task27.task2712.statistics.StatisticsManager; import java.text.DateFormat; import java.text.ParseException; import java.text.SimpleDateFormat; import java.util.*; public class Test { static HashMap<Date, Long> dataRows = new HashMap<>(); static { SimpleDateFormat dateFormat = new SimpleDateFormat("dd-MMM-yyyy", Locale.ENGLISH); try { dataRows.put(dateFormat.parse("13-May-2018"), 250l); dataRows.put(dateFormat.parse("13-May-2018"), 102l); dataRows.put(dateFormat.parse("13-May-2018"), 543l); dataRows.put(dateFormat.parse("10-June-2014"), 450l); dataRows.put(dateFormat.parse("12-June-2012"), 10l); dataRows.put(dateFormat.parse("14-June-2013"), 58941l); } catch (Exception ig) { } } public static void main(String args[]) throws Exception { printAdRevenue(); } static long totalRevenuePerDay; static public void printAdRevenue() { Map<String, Long> adRevenuePerDay = getAdPerDayMap(); totalRevenuePerDay = 0; adRevenuePerDay.forEach((key, value) -> { totalRevenuePerDay += value; System.out.println((String.format(Locale.ENGLISH, "%s - %.2f", key, value / 100.0))); }); System.out.println((String.format(Locale.ENGLISH, "Total - %.2f", totalRevenuePerDay / 100.0))); } static public Map<String, Long> getAdPerDayMap() { SimpleDateFormat dateFormat = new SimpleDateFormat("dd-MMM-yyyy", Locale.ENGLISH); //List<EventDataRow> dataRows = statisticsStorage.storage.get(EventType.VIDEOS_SELECTED); Map<String, Long> revenueByDay = new TreeMap<>(new Comparator<String>() { @Override public int compare(String o1, String o2) { Date dateOne; Date dateTwo; try { dateOne = dateFormat.parse(o1); } catch (ParseException e) { throw new RuntimeException(e); } try { dateTwo = dateFormat.parse(o2); } catch (ParseException e) { throw new RuntimeException(e); } if (dateOne.before(dateTwo)) { return 1; } else if (dateOne.after(dateTwo)) { return -1; } return 0; } }); for (Map.Entry<Date, Long> dataRow : dataRows.entrySet()) { String day = dateFormat.format(dataRow.getKey()); long amount = dataRow.getValue(); revenueByDay.put(day, revenueByDay.getOrDefault(day, 0L) + amount); } return revenueByDay; } }

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Level 41 , Wilson, United States

26 September 2022, 16:14

That was it, smh. Lol, thanks, Guadalupe.

Guadalupe Gagnon

Level 37 , Tampa, United States

26 September 2022, 15:51

I don't think the OrderManager class should be a singleton. It should have a public constructor and the orderQueue should not be static. Try just simply:

//...
private LinkedBlockingQueue<Order> orderQueue = new LinkedBlockingQueue<>();

public OrderManager() { }

@Override
public void update(Observable o, Object arg) {
//...

Thomas

Level 41 , Bayreuth, Germany

26 September 2022, 16:19

wow, good

Level 41 , Wilson, United States

26 September 2022, 17:05

Appreciate your help too, Thomas.