AccountAtBank.JAVA***********************************
import java.util.*;

/**
 * AccountAtBank – The class AccountAtBank represents simplification of a bank account like one you would see at any financial institution.
 *
 * @author: A. Gutierrez
 * @version 2007.02.18
 */

public class AccountAtBank
{
  // Fields of this class

// Interest rate

private static  double m_dCurrentInterestRate;

private static int m_nNextAccountNumber;

//  The current account balance

   private double m_dBalance;

// The customer name

   private String customer;

// The customer Account number

  private int custAccountNumber;

// Constructors

     public AccountAtBank (String customer, double dInitialDeposit)
         {
            this.customer = new String(customer.toUpperCase());
            m_dBalance = dInitialDeposit;


         }

       public AccountAtBank(String customer)
          {
            this.customer = new String(customer.toUpperCase());
            m_dBalance = 0.0;

         }

// Methods

//  Mutator Methods

// Setting a new rate for the account:

public static void rate(double newRate)
{
// Check for a good interest rate
 if (newRate > 0.0 && newRate < 20.0)
   {
      m_dCurrentInterestRate = newRate;
    }
     else
         {
           System.out.println(newRate + " is is not a valid interest rate");
          }
   }

//  Depositing on the account

public void  newDeposit(double amount)
{
    // Checking first for a good deposit

    if ( amount > 0)
      {
        m_dBalance += amount;
       }
     else
         {
           System.out.println(" Your deposit should be positive");
          }
  }

// Withdrawing from an account

public void newWithdrawal(double withdraw)
{
   // Checking first for a good withdraw

    if ( withdraw > 0)
      {
        // Checking that this amount can be withdrawn

         if (m_dBalance >= withdraw)
            {
                m_dBalance -= withdraw;
              }
           else
             {
                System.out.println(" You don’t have enough money");
             }
        }
     else
         {
           System.out.println(" Your withdraw should be positive");
          }
  }

   public void monthlyChanges()
 {
     monthlyFee();
     monthlyInterest();
   }

// Private methods to implement the monthlyChanges

private void monthlyFee()
   {
      m_dBalance += 5.0;    // $5.00 monthly maintenance fee
    }

private void  monthlyInterest()
    {
       m_dBalance +=   m_dBalance*( m_dCurrentInterestRate/1200.0);

// Try to figure out why 1200.0
     }

 public static void putInitialAccountNumber(int newNumber)
    {
     m_nNextAccountNumber = newNumber;
    }

 public void insertAccountNumber()
   {
      custAccountNumber = m_nNextAccountNumber;
      m_nNextAccountNumber++;
   }

//   Accessor Methods

public static double rate()

{
   return  m_dCurrentInterestRate;
}

public double getBalance()
 {
 //  We have here a private variable nCents

   int nCents = (int) (  m_dBalance*100 +0.5);
   return nCents/100.0;
}
 public int getAccountNumber()
 {
  return custAccountNumber;
  }
 public String getCustomer()
  {
  return customer;
  }
  public static int getNextAccountNumber()
 {
  return m_nNextAccountNumber;
  }
}  // End the class definition of AccountAtBank

Bank.JAVA***********************************

import java.util.*;

/**
 * Bank is a collection of AccountAtBank objects.
 * It uses the ArrayList class, so be sure to import the java.util.ArrayList, or the java.util.* package

 *
 * @author: A. Gutierrez
 * @version 2007.02.07
 */

public class Bank
{
 // Storage for an arbitrary number of AccountAtBank objects

    private ArrayList<AccountAtBank> bankAccounts;

 // Storage for an arbitrary number of Client objects

   private ArrayList<Client> clients;


  public Scanner myScanner = new Scanner(System.in);

  // Constructor

   public Bank()
  {
    bankAccounts = new ArrayList<AccountAtBank>();
    clients = new ArrayList<Client>();
   }

  // Mutators

    public static void initializeBank()

   {// Setting the interest rate for the customers in the bank
     AccountAtBank.rate(5);

  // Setting the nex Account number in the bank
   AccountAtBank.putInitialAccountNumber(1);
   }

 public void storeBankAccount(AccountAtBank nAccount)
    {
   /* Check that the account does not exist, before inserting it into the
    * ArrayList.
    */
      boolean exists = existName(nAccount);
      if (exists)
          System.out.println("This client already has an account");
      else
        {
        // If the client does not exist, include it, after inserting account number
         nAccount.insertAccountNumber();
         bankAccounts.add(nAccount);
        // Because this is a new client, increment the next account number
      }
    }

    public void storeClient(Client nClient)
    {
       clients.add(nClient);
    }


    public void removeBankAccount(int accountNumber)
    {
     AccountAtBank accountToDelete = retrieveAccount(accountNumber);
     String custName = accountToDelete.getCustomer();
     System.out.println("Is the account of " + custName +" the one you want to delete?");
     System.out.println("Please enter y/n.");
     System.out.print(">");

      //Gets the next String of data from the keyboard up to a "\n" and stores it in name
      String answer = myScanner.nextLine();
      // Convert the answer to upper case to establish a canonical form for the answer
      answer = new String(answer.trim().toUpperCase());
         if (answer.equals("Y"))
            {
              bankAccounts.remove(accountToDelete);
            }
          else
            {
              System.out.println("You should verify the account you want to delete");
            }
      }

   // Accessors

   //  For the bank accounts

   public int numberOfAccounts()
   {
    return bankAccounts.size();
   }

   public boolean existName(AccountAtBank nAccount)
   {
      Iterator<AccountAtBank> iterAccounts = bankAccounts.iterator();
     boolean found = false;
     AccountAtBank checkAccount;
     String nName = nAccount.getCustomer();
     while (iterAccounts.hasNext() && !found)
       {
         checkAccount = iterAccounts.next();
        if (checkAccount.getCustomer().equals(nName) )
            found = true;
        }
     return found;
   }


public void showAccount(int accountNumber)
   {
    AccountAtBank accountToShow =  retrieveAccount(accountNumber);
    if (accountToShow != null)
    {
      System.out.println("The account belong to " + accountToShow.getCustomer());
     System.out.println("The balance in the account is $" + accountToShow.getBalance());
    }
    else
    {
     System.out.print ("The account number " + accountNumber);
     System.out.println(" is not a valid account number");
     }
   } // End of showAccount

public AccountAtBank retrieveAccount(int accountNumber)
 {
   Iterator<AccountAtBank> iterAccounts = bankAccounts.iterator();
   boolean found = false;
     AccountAtBank checkAccount = null;
     while (iterAccounts.hasNext() && !found)
       {
         checkAccount = iterAccounts.next();
        if (checkAccount.getAccountNumber() == accountNumber )
            found = true;
        }
     if (found)
        return checkAccount;
     else
        return null;
   }
public Client retrieveClient(String custName, int custAccount)
{
 Iterator<Client> iterClients =  clients.iterator();
 boolean found = false;
 Client checkClient = null;
 while (iterClients.hasNext() && !found)
   {
    checkClient = iterClients.next();
    if(checkClient.getOwner().equals(custName) &&
          (checkClient.getAccountNumber() == custAccount))
              {
               found = true;
              }
   }
  if(found)
    return checkClient;
  else
    return null;
}


  public AccountAtBank getBankAccount(String custName)
    {
     Iterator<AccountAtBank> iterAccounts = bankAccounts.iterator();
    boolean found = false;
     AccountAtBank checkAccount = null;
     while (iterAccounts.hasNext() && !found)
       {
         checkAccount = iterAccounts.next();
         if (checkAccount.getCustomer().equals(custName) )
            found = true;
        }
     if (found)
        return checkAccount;
     else
        return null;
   } // End of getBankAccount

  } // End of Bank class
CLIENT.JAVA***********************************

/*
Now we define the class of owner of the Account at the Bank
**/

public class Client
{
  // First field is the name of the client
   private String owner;

  // Second field is the amount to be deposited each month

   private double monDeposit;

  // Third field is the account number assigned to his/her account
   private int accountNumber;

// Constructors
  public Client(String name)
  {
    owner = new String(name);
    accountNumber = 0;
    monDeposit = 0.0;
   }

  public Client(String name, double deposit)
  {
    owner = new String(name);
    accountNumber = 0;
    monDeposit = deposit;
   }

  // Mutator

  public void putAccountNumber(int myNumber)
  {
    accountNumber = myNumber;
   }
  public void  newDeposit(double newDepo)
  {
       monDeposit = newDepo;
   }

  // Accessors

   public String getOwner()
   {
     return owner;
    }
  public int getAccountNumber()
  {
   return accountNumber;
  }
  public double getMDeposit()
  {
   return monDeposit;
   }
} // End of the Client class

RUNNINGABANK.JAVA***********************************

/**
 * RunningABank is a program to create, remove, display accounts.
 *
 * @author: A. Gutierrez
 * @version 2007.02.28
 */

import java.util.*;

public class RunningABank
{
private static Scanner myInputs = new Scanner(System.in);
 // Creating the ArrayLists !!
private static Bank fedBank = new Bank();

  public static void main(String args[])
  {
    // Set the rate for the bank, and the next account number

   fedBank.initializeBank();

    // Menu
    int choice = 0;

   while (choice != 4)
   {
     System.out.println();
     System.out.println("Choose the number for your option:");
     System.out.println();
     System.out.println("To create an account: ..........1");
     System.out.println();
     System.out.println("To remove an account: ..........2");
     System.out.println();
     System.out.println("To display an account: .........3");
     System.out.println();
     System.out.println("To finish: .....................4");
     System.out.println();
     System.out.println("Please enter your choice.");
     System.out.print(">");
     choice = myInputs.nextInt();
     myInputs.nextLine();
     switch (choice)
     {
      case 1:  createAccount();
               break;
      case 2:  removeAccount();
               break;
      case 3:  displayAccount();
               break;
     case 4:  break;
      default: System.out.print("Your choice should be a number between");
               System.out.println(" 1 and 4. You entered " + choice);
      } // End switch
     } // End while
    } // End main

     public static void createAccount()
     {
      String name = getCustomerName("create");
      double initialDeposit = -1;
      do
      {
        System.out.print("Enter the initial deposit on the account:  ");

        initialDeposit = myInputs.nextDouble();
        if (initialDeposit < 0.0)
          {
           System.out.println("The Deposit should be a positive number. Try again");
           System.out.println();
           }

       } while (initialDeposit < 0.0);

      System.out.println();
      AccountAtBank nBankAccount = new AccountAtBank(name, initialDeposit);
      Client nClient = new Client(name,initialDeposit);
      nClient.putAccountNumber(nBankAccount.getAccountNumber());
      fedBank.storeBankAccount(nBankAccount);
      fedBank.storeClient(nClient);
      }

      public static void removeAccount()
       {
        String name = getCustomerName("remove");
        AccountAtBank accountToRemove = fedBank.getBankAccount(name);
         if (accountToRemove != null)
         {
         int clientAccount = accountToRemove.getAccountNumber();
   //       System.out.println("The account you want to remove has number "+clientAccount);
          System.out.println();
         fedBank.removeBankAccount(clientAccount);
         }
        else
          System.out.println("We could not find the account of " + name);
       } // End of removeAccount

      public static void displayAccount()
      {
        String name = getCustomerName("display");
        AccountAtBank accountToShow = fedBank.getBankAccount(name);
        if (accountToShow != null)
         {
          int clientAccount = accountToShow.getAccountNumber();
     //     System.out.println("The account you want to display has number "+ clientAccount);
          System.out.println();
         fedBank.showAccount(clientAccount);
         }
        else
          System.out.println(name +" does not have an account" );
       } //. End of displayAccount

      public static String getCustomerName(String action)
      {
        System.out.println();
        System.out.print("Enter the name of the customer whose account");
        System.out.print(" you want to " + action+ ":  ");
        String name;
       do
         {
           name = myInputs.nextLine();
           name = new String(name.trim().toUpperCase());
         }
        while (name.equals(""));
        System.out.println();
        return name;
       }

 }  // End of Running a Bank