Chapter 4, Problem 56E

Open the products project and complete the StockManager class through this and the next few exercises. StockManager uses an ArrayList to store Product tems. Its addProduct method already adds a product to the collection, but the following methods need completing: delivery, findProduct, printProductDetaiIs, and numberInStock.

Each product sold by the company is represented by an instance of the Product class, which records a product's ID, name, and how many of that product are currently In stock. The Product class defines the increaseQuantity method to record increases in the stock level of that product. The sell One method records that one Item of that product has been sold, by reducing the quantity field level by 1. Product has been provided for you, and you should not need to make any alterations to it.

Start by implementing the printProductDetai1s method to ensure that you are able to iterate over the collection of products. Just print out the details of each Product returned, by calling its toString method.