2 arraylists for one program

Question

In my program I have 2 store locations Callahan and Lambton, within the current code I have there is only one array list. My question is, is there a way to keep the one arraylist but have it separate for when the user enters a different store name? The following code is the menu system which will call the arraylist size and display it.

import java.util.Scanner;
import java.util.*;
import java.util.ArrayList;

public class StarberksInterface
{


public static void main(String args[])
{

    Scanner console = new Scanner(System.in);
    store = new Store();
    String str, sName1, sName2, name;
    char c;
    int n=0;
    sName1 = "Callahan";
    sName2 = "Lambton";



    while(n!=5)// Exits the program when 5 is pressed
        {

            //This is the main menu that will be displayed first.
            System.out.println("       MAIN MENU FOR MANAGEMENT SYSTEM");
            System.out.println("===============================================");
            System.out.println("1. CHOOSE STORE");
            System.out.println("2. DISPLAY STORES");
            System.out.println("3. LOAD STORE VIA FILE");
            System.out.println("4. SAVE STORE TO FILE ");
            System.out.println("5. EXIT PROGRAM");
            System.out.println("===============================================");

            System.out.print("\n Please enter option 1-5 to continue...: ");
            n = Integer.parseInt(System.console().readLine());
            // Reads user input and takes them to selected code.
            if (n>5||n<1)
            {
                System.out.print("Invalid input, please try again...");
                continue;
            }
            if (n==1)// Takes to option 1 or sub menu
            {
                str="y";

                while(str.equals("y")||str.equals("Y"))
                {
                    System.out.println("Enter a store name [Callahan or Lambton] ");
                    name = console.next();
                    if (sName1.equals(name)|| sName2.equals(name))
                    {
                        StarberksInterface.subMenu();
                        break;

                    }

                    else 
                    {
                        System.out.println("There is no store under this name. Please try again.");
                    }

                }
                continue;
            }
            if (n==2)// Gathers products in stores and displays the number of products
            {
                System.out.println(" Store data is being displayed.");
                System.out.println("===============================");
                System.out.println("Store: Callahan");
                System.out.println("       Number of products: "+store.getProductListSize());
                System.out.println("===============================\n");
                System.out.println("Store: Lambton");
                System.out.println("       Number of Products: "+store.getProductListSize());
                System.out.println("===============================\n");

            }
        }
}




 public static void subMenu()
 {
Scanner console = new Scanner(System.in);
String str;
char c;
int n=0;


        // this will be the sub menu that gets displayed.
        System.out.println("        INVENTORY MANAGEMENT SYSTEM");
        System.out.println("===============================================");
        System.out.println("1. ADD PRODUCT DATA");
        System.out.println("2. VIEW SINGLE PRODUCT DATA");
        System.out.println("3. DELETE PRODUCT");
        System.out.println("4. DISPLAY ALL PRODUCTS IN STORE");
        System.out.println("===============================================");
        System.out.println("5. EXIT SUB MENU");

        while(n!=5)// Exits the program when 4 is pressed
        {
            System.out.print("\n Please enter option 1-5 to continue...: ");
            n = Integer.parseInt(System.console().readLine());
            // Reads user input and takes them to selected code.
            if (n>5||n<1)
            {
                System.out.print("Invalid input, please try again...");
                continue;
            }
            if (n==1)// Takes to option 1 or addItem()
            {
                str="y";
                while(str.equals("y")||str.equals("Y"))
                {

                    StarberksInterface.addItem();
                    System.out.print("Would you like to enter another product ? (Y or N) : ");
                    str = console.next();
                }   
                continue;
            }
            if (n==2)// Takes to option 2 or prodData
            {
                str="y";
                while(str.equals("y")||str.equals("Y"))
                {
                    StarberksInterface.prodData();
                    System.out.println("\n***************************************************\n");
                    System.out.print("Stay viewing this page? (Y or N) ");
                    str = console.next();

                }
                continue;
            }

            if (n==3)// Takes to option 3 or delete item
            {
                System.out.print("Delete a product");
                continue;
            }

            if (n==4)// Takes to option 4 or view all products in store
            {
                System.out.print("Displaying all products in store");
                continue;
            }
        }
            if (product != null)// If there is information on the system
            // then the user will have the option to view data, before the program quits
            {
                System.out.println("\n***************************************************\n");
                System.out.println("\nAre you sure you want to quit? There is information stored on a product. ");
                System.out.println("\nWould you like to view if information? (Y / N) ");
                str="";
                str = console.next();
                while(str.equals("y")||str.equals("Y"))
                {

                    StarberksInterface.prodData();
                    return;
                }

            }

            else
            {
                System.out.print("\nThank you for using this inventory management software.\n");
                System.out.print("Developed by Xavier Edwards");
                System.out.println("\n***************************************************\n");
            }
 }

The following code is where the arraylist gets populated

public static Product product;
public static Store store;
// Where the user inputs the data for the item
public static void addItem ()
{
    Scanner console = new Scanner(System.in);
    product = new Product();// initiates the product and store to being empty.


    String desc, id, str="";
    double price = 0, sUpPrice = 0, unitCost = 0, inventoryCost = 0;
    int stock = 0, demand = 0;


        System.out.print("Please enter product description between 3 to 10 characters...: ");
        desc = console.next();
        desc = desc.toLowerCase();
        product.setName(desc);


        if ((desc.length() < 3 || desc.length() > 10))
        {
            System.out.println("\nThis Input is incorrect. Please make description between 3 to 10 characters.\n");
            System.out.println("Try again with different input. ");
            System.out.println("\n*****************************************\n");
            StarberksInterface.addItem();
        }

        System.out.print("Please enter price in $ : ");
        price = console.nextDouble();
        product.setPrice(price);

        if (price < 0)
        {
            System.out.println("\nThis Input is incorrect. Please make sure attributes are positve numbers\n");
            System.out.println("Because of incorrect input, program will restart. ");
            System.out.println("\n*****************************************\n");
            StarberksInterface.addItem();
        }

        System.out.print("Please enter set up price. $ : ");
        sUpPrice = console.nextDouble();
        product.setsUpPrice(sUpPrice);

        if (sUpPrice < 0)
        {
            System.out.println("\nThis Input is incorrect. Please make sure attributes are positve numbers\n");
            System.out.println("Because of incorrect input, program will restart. ");
            System.out.println("\n*****************************************\n");
            StarberksInterface.addItem();
        }

        System.out.print("Please enter unit- cost. $ : ");
        unitCost = console.nextDouble();
        product.setunitCost(unitCost);

        if (unitCost < 0)
        {
            System.out.println("\nThis Input is incorrect. Please make sure attributes are positve numbers\n");
            System.out.println("Because of incorrect input, program will restart. ");
            System.out.println("\n*****************************************\n");
            StarberksInterface.addItem();
        }

        System.out.print("Please enter the inventory cost. $ : ");
        inventoryCost = console.nextDouble();
        product.setinvCost(inventoryCost);

        if (inventoryCost < 0)
        {
            System.out.println("\nThis Input is incorrect. Please make sure attributes are positve numbers\n");
            System.out.println("Because of incorrect input, program will restart. ");
            System.out.println("\n*****************************************\n");
            StarberksInterface.addItem();
        }

        System.out.print("Please enter the amount in stock : ");
        stock = console.nextInt();
        product.setstock(stock);

        if (stock < 0)
        {
            System.out.println("\nThis Input is incorrect. Please make sure attributes are positve numbers\n");
            System.out.println("Because of incorrect input, program will restart. ");
            System.out.println("\n*****************************************\n");
            StarberksInterface.addItem();
        }

        System.out.print("Please enter the demand of the product : ");
        demand = console.nextInt();
        product.setdRate(demand);

        if (demand < 0)
        {
            System.out.println("\nThis Input is incorrect. Please make sure attributes are positve numbers\n");
            System.out.println("Because of incorrect input, program will restart. ");
            System.out.println("\n*****************************************\n");
            StarberksInterface.addItem();
        }

        System.out.println("\n*****************************************\n");
        System.out.print(desc +" Product was added successfully ");
        System.out.println("\n*****************************************\n");
        // stores the item in the array


        //Checks to see if item is already in the list
        /*while (product != null)
        {
            if (product.equals(store.getProduct(desc)))
            {
                System.out.println(desc +" is already a product.");
                System.out.println("Input for data will restart");
                StarberksInterface.addItem();
            }
        }*/

        store.add(product);

}

and this last bit of code is the actual arraylist

import java.util.ArrayList;

public class Store{
// stores the product information in an array list
//allows for numerous products and each can be called in the Starberks Interface
public ArrayList <Product> ProductList = new ArrayList<Product> ();

public Store()
{

}
public int getProductListSize()
{
    return ProductList.size();
}

public void add(Product product)
{   
    // Adds the product and all details entered by user to the list.        
    ProductList.add(product);
}

public Product getProduct(String prodName) {
    //
    for (int i = 0; i < ProductList.size(); i++) {
            //searches through list of products to find a specific name entered in
            // from the Starberks Interface
        if (ProductList.get(i).getName().equals(prodName)) {
            return ProductList.get(i);
        }
    }
    return null;
   }

  }

Answer 1

You want to do an ArrayList split into 2. Unfortunately, if you want to do something like that, you will need to look into another data structure. You could use a Map> instead, to map each ArrayList of products to its store.

Although, the best way to do that would be have a more OO approach and have an ArrayList inside Store class.

Answer 2

Create two stores

Store callahan = new Store();
Store lambton = new Store();

Add product to corresponding store based on your input

  if(storeName.equals("callhan")) {
      callahan.add(product);
  } else {
      lambton.add(product);
  }

Even better you can create a map of stores.

   Map<String, Store> stores = new HashMap<>();
   stores.put("callahan", new Store());
   stores.put("lambton", new Store()));

And so your product adding codes would be

   stores.get(storeName).add(product);

Answer 3

You could try an ArrayList of an ArrayList, it's not keeping it to one list, but should have the flexibility that you're wanting.

Answer 4

As far I understand you are trying to retrieve products from a ProductList based on the Store.

I would recommend populating the ProductList outside the Store class to a MasterProductsclass. This ProductList would serve as a master Products list.

So whenever you want to addItem() to a Store you can add the Product to the ProductList with your Custom method as setStoreHavingProduct method and add Store name value to it. Before addItem() verify if the ProductList contains same Product and if it does append more Store names. So ProductList will contain all products and inside them all Store that have this Product.

This way you can finally overide contains method of the ProductList and display only subList based on the Store.