VendingMachine and ItemType

Question

Hi folks! I am modelling a Vending machine. Could anyone please answer the comments inside my code.
Vending machine class uses ItemType class
import java.lang.*;
import java.util.*;
import type.lang.*;
public class ItemType
    public ItemType(String n, int p, int quantity)
       name = n;
       f = p;
       quantin = quantity;
    public void addItems(int m)
       quantin += m;
    public void getItem(int sell) 
       quantin -= sell;
    public String getName()
       String out = name;
       return out;
    public int getPrice()
       int price = f;
       return price;
    public int getQuantity()
         int quan = quantin;
         return quan;
    private String name;
    private int f;
    private int quantin;
    final static int MAX_QUANTITY = 15;
import java.lang.*;
import java.util.*;
import type.lang.*;
public class VendingMachine
    public void VendingMachine()
  // Adds items into VendingMachine collection
    public void addItemType(ItemType item)
    ItemType aitem = item;
    int i = 0;
    i++;
  /*How can I put the key and the object reference to "ItemType" in this bag?
    I can add and remove items from this bag, and the key should automatically arrange
    itself (i.e. if I remove item with key 3 then item with key 4 will become item with
    key 3
   Is it suitable to use TreeMap over here?
    bag.put(i, aitem);
    public int clearMoney()
   // counts the amount of coin deposited
    public void depositCoin(int cents)
    int acents = cents;
    inamount = amount + cents;
   //gets the amount of coins in BankAccount
    public int getBankAccount()
   //gets the total amount deposited and
   //throws exception if not sufficient payment is made
    public int getDepositAmount()
    return inamount;
    if (inamount < bag.get(i).getPrice)
    throw new InsufficientPaymentException("Not enough payment!");
   public void removeItemType(int which)
   bag.remove(which);
   public void reStock(int which, int qty);
   if (bag.containsKey(which))
   bag.get(which).addItems(qty);
   public int selectItem(int which)
   if (bag.containsKey(which) && bag.get(which).getQuantity > 0)
   bag.get(which).getQuantity() - 1; // dispenses the item!!
  } else throw new OutOfStockException("Out of Stock!");
  int in = which;
  return in;
  } //end of selectItem
   public string showItems()
  for (int i = 0; i < bag.size(); i++)
   String in = ""+i;
   String show = (String) bag.get(in)+ (String) (bag.get(in)).getName();
   // Here .getName() method of ItemType class is giving me "cannot resolve symbol"
   //why is it so?
   return show;
   public string toString()
   private ItemType in;
   public int inamount;
   public int selected;
   private TreeMap bag = new TreeMap();
Thanks a lot for any help!!! : )

Answer 1

/*How can I put the key and the object reference to
"ItemType" in this bag?
I can add and remove items from this bag, and the key
should automatically arrange
itself (i.e. if I remove item with key 3 then item
with key 4 will become item with
key 3
Is it suitable to use TreeMap over here?A Map is not appropriate for this. Look at Lists (stacks) instead. Now, a Map of Stacks isn't such a bad plan...
String show = (String) bag.get(in)+ (String) (bag.get(in)).getName();
// Here .getName() method of ItemType class is giving
me "cannot resolve symbol"
//why is it so?You're casting it as a String and wondering why you can't call getName() on it? I haven't looked at what you're actually storing (ItemType), but if it's anything but a String, you're going to have to change your cast. Also, you'll probably have to change it to ((ItemType) bag.get(in)).getName();Note the parentheses...