Java 9 Programming By Example

Implementing inventory

Now that we have discussed a lot of technologies and programming approach, it is very much the time to implement some sample code. We will implement inventory keeping in our application using reactive streams. For the example, the inventory will be very simple. It is a Map<Product,InventoryItem> that holds the number of items for each product. The actual map is ConcurrentHashMap and the InventoryItem class is a bit more complex than a Long number to properly handle concurrency issues. When we design a program that is built on responsive streams, we do not need to deal with much concurrency locking, but we still should be aware that the code runs in a multithread environment and may exhibit strange behavior if we do ...