Get specific element from ArrayList

Question

In main I do this: First I create a new customer with its first name, lastname and number. Then I create two savingsAccounts, with its amount, id and interest rate. I then add the two savingsAccounts to the new customer. Finally I add the new customer to the bank.

Customer newCustomer = new Customer(firstName, lastName, pnumber);    

SavingsAccount savingsAccount1 = new SavingsAccount(400, "1", 4); //400$ into account no.1, with interest 4%
SavingsAccount savingsAccount2 = new SavingsAccount(300, "2", 3);

newCustomer.addAccount(savingsAccount1);  
newCustomer.addAccount(savingsAccount2);  

bank.addCustomer(newCustomer);

Here is class Bank:

public class Bank {
    String bankName;    
    private ArrayList<Customer> customers = new ArrayList<Customer>(); 

    Bank(String bankName) {
        this.bankName = bankName;
    }

    public void addCustomer(Customer newCustomer) {
        customers.add(newCustomer);
    }
}

Here is class Customer:

public class Customer {
    private String firstName;
    private String lastName;
    private String number;      
    private ArrayList<Account> accounts;

    Customer(String firstName, String lastName, String number) { 
        this.firstName = firstName;
        this.lastName = lastName;
        this.number = number;
        this.accounts = new ArrayList<Account>();
    }

    public void addAccount(SavingsAccount account) {
        accounts.add(account);
    }

    public void addAccount(CreditAccount account) {
        accounts.add(account);
    }

    public ArrayList<Account> getAccounts() {
        return accounts;
    }
}

Here is class SavingsAccount (that inherits class Account):

public class SavingsAccount extends Account {

    public SavingsAccount() {     
        super();
    }

    public SavingsAccount(double bal, String id, double inte) {   
       super(bal, id, inte);
    }

    @Override
    public void deposit(String number, String id, double amount) {

    }

    @Override
    public void withdraw(String number, String id, double amount) {

    }

    @Override
    public void transfer(String number, String id, double amount) {

   }

    @Override  
    public double getBalance() {

    }

    @Override
    public String getAccountId() {
        return accountId;
    }

    @Override
    public double getInterest(){
        return interest;
    }
}

My problem is: How can I write code in class SavingsAccount to deposit, withdraw, transfer money for a certain customer, for a certain account? Let's say I want to deposit 500 to customer no.2 on his account no.1.

That should be something like savingsAccount.deposit("2", "1", 500);

I just can't figure out how to access customer number 2, and his account number 1. Can anyone help me please?

Why would this method be in this class ? Seems more logical to have in in Customer, since it is the only class who knows all the Accounts related to a specific Customer. — Dici
– Dici, Commented Sep 20, 2014 at 22:34
@Dici ok, so if I put it in class Account, how can I access the right customer and account? How can the code look like? — user2939293
– user2939293, Commented Sep 20, 2014 at 22:39
This is how I would do it - Iterate over Bank customers to find if there is a customer whose id==2. If found, then iterate over all the accounts of that customer to find an account with no. == 1. If found, do somthing with that account like add or remove money. — sid smith
– sid smith, Commented Sep 20, 2014 at 22:41
It would be better to use a Map<String,Customer> in your Bank (unless the ids are consecutive integers). This way, the lookup would be more efficient. — Dici
– Dici, Commented Sep 20, 2014 at 22:42

engineercoding · Accepted Answer · 2014-09-20 22:52:26Z

2

What you could do is have a method for that in the Bank class:

public class Bank {
  // Your stuff
  // new method:
  public boolean transfer(Account accountFrom, double amount, String nameTo, int account) {
     //check if the balance can be deposit from the account
     if(amount <= accountFrom.getBalance()) {
        //Check if the person exists in the bank
        String name = nameTo.split(" "); // name[0] is the first name, name[1] last name

        boolean success = false;
        for(Customer c: customers) {
           if(c.getFirstName().equalsIgnoreCase(name[0]) &&
                     c.getLastName().equalsIgnoreCase(name[1]) {
              for(Account a : c.getAccounts()) {
                 if(a.getAccountId() == account) {
                    // Add it to the account
                    a.deposit(amount);
                    success = true;
                    break;
                 }
              }
              break;
           }
        }

        // Deposit it from the account (That class should only keep track of money, so it 
        // only takes an argument to deposit or withdraw a value, the rest is done by the bank
        // Only do this if money has been dsposited at the target account
        if(success){
          accountFrom.withdraw(amount);
          return true;
        }

     }
     return false;
  }
}

For this to happen you have to structurely change your setup.

Have the accounts only manage money, those accounts get added to a customer. The customer is the person who communicates between the bank and himself. And finally the bank communicates with customers.

I hope this will help you in the direction

answered Sep 20, 2014 at 22:52

engineercoding

8326 silver badges14 bronze badges

Sign up to request clarification or add additional context in comments.

1 Comment

user2939293 Over a year ago

thank you. I think the transfer method is too complicated to begin with. Can you show me a simplier method, like deposit or withdraw? I don't understand your explanation above, what do you mean by "those accounts get added to a customer"?.

Collectives™ on Stack Overflow

Get specific element from ArrayList

1 Answer 1

1 Comment

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

1 Comment

Your Answer

Sign up or log in

Post as a guest

Related