Class InventorySystem

InventorySystem.java:6–48

import java.util.Map;

public class InventorySystem {

    static Map<String, Product> productMap = new HashMap<>();
    static Map<Location, Unit> locationMap = new HashMap<>();

    public static void addProduct(Product product) {
        productMap.put(product.id, product);
    }

    public static Product getProduct(String product) {
        return productMap.get(product);
    }

    public static void placeUnit(Unit unit) {
        for (Map.Entry<Location, Unit> entry: locationMap.entrySet()){
            // if (SimpleStrategy.works())
            //get lock on entry.getKey()
                if(entry.getValue()==null){
                    unit.locationId = entry.getKey().id;
                }
                //release lock
            }
    }

    public static void removeUnit(Product product) {
        for (Map.Entry<Location, Unit> entry: locationMap.entrySet()){
            // if (SimpleStrategy.works())
            //get lock on entry.getKey()
            if(entry.getValue()!=null && product.id.equals(entry.getValue().productId)){
                locationMap.remove(entry.getKey());
            }
            //release lock
        }
    }

    public static Map<Location, Unit> getShelvesStatus(){
        return locationMap;
    }

    public static void updateStatus(Unit unit, Status status){
        unit.status = status;
    }
}

class SimpleStrategy {