Package cs2110

Class GrocerySimulator

java.lang.Object

cs2110.GrocerySimulator

public class GrocerySimulator
extends Object

An interactive simulation of one customer shopping at a grocery store.

Field Summary

Fields

Modifier and Type	Field	Description
private boolean	afterCheckout	Whether the customer has started checking out.
private final Cart	cart	The shopping cart for the customer being simulated.
private final Coupon[]	coupons	An array of coupons that are currently valid at the store.
private RegisterTransaction	register	The register to use for applying coupons and printing a receipt when the customer checks out.
private final boolean[]	scanned	An array that tracks which coupons have been scanned (either successfully or unsuccessfully) during the simulation.
private final Store	store	The inventory of the grocery store being simulated.

Constructor Summary

Constructors

Constructor	Description
GrocerySimulator(String name)	Constructor for the grocery simulator.

Method Summary

Modifier and Type	Method	Description
private void	getCommandHelp()	Print a message to the console listing available commands and their effects.
private void	invalidCommand(String cmd)	Let the user know if the command that they typed is invalid.
static void	main(String[] args)	Runs the grocery simulator program, either by accepting commands one at a time through the console or by batch processing a text file line-by-line that is passed in as a program argument.
private void	processCartAdd(String[] command)	Process an "addtocart" command.
private void	processCartList()	Process a "listcart" command by listing the items currently in the cart.
private void	processCartRemove(String[] command)	Process a "removefromcart" command.
private void	processCheckout()	Process the "checkout" command by initializing the register transaction with the current cart contents.
private void	processCommands(Scanner sc, boolean echo)	Read commands from a Scanner and execute them.
private void	processCouponList()	Process a "listcoupon" command by listing the coupons that have not been scanned.
private void	processCouponScan(String[] command)	Process a "scancoupon" command.
private boolean	processPay()	Process the "pay" command by printing the (sorted) receipt and exiting the simulator.
private static String	sortReceiptItems(String unsorted)	Rearranges the items on the receipt into alphabetical order.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Details

store

private final Store store

The inventory of the grocery store being simulated.

cart

private final Cart cart

The shopping cart for the customer being simulated. Items must be conserved between `store` and `cart`.

register

private RegisterTransaction register

The register to use for applying coupons and printing a receipt when the customer checks out.

coupons

private final Coupon[] coupons

An array of coupons that are currently valid at the store. Each of these coupons has a unique `id()`, and no entries of this array are null.

scanned

private final boolean[] scanned

An array that tracks which coupons have been scanned (either successfully or unsuccessfully) during the simulation. The indices of `applied` and `coupons` correspond, so `applied[i]` is true if and only if `coupons[i]` was scanned.

afterCheckout

private boolean afterCheckout

Whether the customer has started checking out. This is the "state" of the simulator's finite state machine, which determines which commands are currently valid.

Constructor Details

GrocerySimulator

public GrocerySimulator(String name)
                 throws FileNotFoundException

Constructor for the grocery simulator. Takes as input a String `name` and parses the file "`name`.sim" to initialize the store inventory and list of coupons. Throws an exception if the simulation file cannot be found.

Throws:

FileNotFoundException

Method Details

main

public static void main(String[] args)

Runs the grocery simulator program, either by accepting commands one at a time through the console or by batch processing a text file line-by-line that is passed in as a program argument.

processCommands

private void processCommands(Scanner sc,
 boolean echo)

Read commands from a Scanner and execute them. Return when the "exit" command is read or when simulation is completed by the "pay" command. If `echo` is true, print the read command after the prompt.

processCouponList

private void processCouponList()

Process a "listcoupon" command by listing the coupons that have not been scanned.

processCartList

private void processCartList()

Process a "listcart" command by listing the items currently in the cart.

processCartAdd

private void processCartAdd(String[] command)

Process an "addtocart" command. First, checks whether the command was issued at an appropriate time (between entering the store and checking out) and prints an error message if not. Then, checks to ensure that the command has exactly one additional argument (the item code) and prints an error message if not. Then, attempts to add an item to the cart with the specified item code with three possible results. 1. If the cart is already full, print "Cart is already full. You cannot add another item." 2. If the cart is not full but the store does not have any items with this code in stock, print "This item has no units in stock." 3. If the cart is not full and the store has an item with this code in stock, unshelve and add it to the cart and print "item_name added to cart." where item_name is the String obtained from the `name()` method of the added item.

processCartRemove

private void processCartRemove(String[] command)

Process a "removefromcart" command. First, checks whether the command was issued at an appropriate time (between entering the store and checking out) and prints an error message if not. Then, checks to ensure that the command has exactly one additional argument (the item code) and prints an error message if not. Then, attempts to remove an item from the cart with the specified item code with two possible results. 1. If the cart did not contain such an item, print "There was no item with this code in your cart." 2. If the cart contained such an item, remove and reshelve it and print "item_name removed from cart." where item_name is the String obtained from the `name()` method of the removed item.

processCheckout

private void processCheckout()

Process the "checkout" command by initializing the register transaction with the current cart contents.

processCouponScan

private void processCouponScan(String[] command)

Process a "scancoupon" command. First, checks whether the user has checked out with the "checkout" command and prints an error message if not. Then, checks to ensure that the command has exactly one additional argument (the coupon id) and prints an error message if not. Then, attempts to locate and scan the coupon, with three possible results. 1. If there is no coupon with the given id, print "A coupon with this id could not be found." 2. If there is a coupon with the given id, but it cannot be applied, print "This coupon could not be applied." 3. If there is a coupon with the given id and it can be applied, apply it and print "Coupon applied!".

processPay

private boolean processPay()

Process the "pay" command by printing the (sorted) receipt and exiting the simulator.

sortReceiptItems

private static String sortReceiptItems(String unsorted)

Rearranges the items on the receipt into alphabetical order. This produces a canonical receipt for each transaction that can be verified during testing.

getCommandHelp

private void getCommandHelp()

Print a message to the console listing available commands and their effects.

invalidCommand

private void invalidCommand(String cmd)

Let the user know if the command that they typed is invalid.