COE318 – Lab 3: Bank Accounts Solution

Objectives
● Implement an Account class.
● Implement a Bank class.
● Use loops.
● Use arrays.
● Write one of the classes from scratch (no template given as in previous labs)

Duration: one week.
Grading Scheme:
50% submitted source code
25% in-class demonstration and questions (during week 4 lab hours)
25% in-class quiz – Held during the first 5 mins of the lab class (during week 6 lab hours)
Overview
A classic application of object-oriented techniques is a bank account. In this lab, you will implement a simplified model of a bank account and of a bank itself.
A bank Account will track the account number, the owner's name and the current balance. The only operations allowed (apart from trivial getters) will be withdrawing and depositing money. A user will not be allowed to make a deposit or withdrawal of a negative or zero value. Furthermore, they will not be allowed to withdraw more money than they have in the account.
An account, of course, must belong to a specific bank; hence you will also implement the Bank class. A Bank object will keep track of all of the accounts it has; it will also disallow two accounts with the same account number.

The Account Class
No template is given for the Account class, you will have to create it from scratch following the design instructions given here.
The Account class will consist of instance variables, a constructor and the following methods:
● String getName()
● double getBalance()
● int getNumber()
● boolean deposit(double amount)
● boolean withdraw(double amount)
In addition, you are provided with a toString() method below that you must not modify.
Account class toString() code
@Override public String toString() {//DO NOT MODIFY return "(" + getName() + ", " + getNumber() + ", " +
String.format("$%.2f", getBalance()) + ")";
}
The Constructor
The constructor's signature is:
public Account(String name, int number, double initialBalance)
In typical use, it could create an account for “Alice Jones” with an account number of 1234 and an initial balance of $100.00 with:
Account alice = new Account(“Alice Jones”, 1234, 100.0);
When you implement the constructor, you must also think about the instance variables you will need. (Hint: recall that a constructor often simply copies its arguments into instance variables. Also, if you have declared your instance variables, a Netbeans tool can be used to generate the code for the constructor automatically.) The Getters
You should have little trouble implementing the getter methods (getName() returns the name of the account owner, getNumber() returns the account number and getBalance() returns the current balance.)
(Hint: The getters can be generated automatically in Netbeans as one of the Refactoring choices.)
The withdraw() and deposit() methods
Note that these methods return a boolean: true or false. If successful, they return true. However, an attempt to withdraw can fail if the balance is not big enough or if an attempt is made to withdraw zero or a negative value. A deposit can fail if the amount is negative or zero.
Of course, a successful deposit or withdrawal should update the account balance.

The Bank Class
You should not attempt to implement the Bank class until you have an Account working properly.
The Bank implementation will require that you use arrays and loops for the first time.
Unlike the Account class, you are given a template for this class (Bank.java) so you don't have to start it from scratch. And, to make your life a little easier and ensure that you start off the right way, the instance variables and the constructor have been given to you as well. (You should not modify the furnished constructor and you do not need any additional instance variables.)

Source Code
Bank.java, MainAccount.java and MainBank.java classes are provided with the lab. More details about these classes are in the instructions below.

Step 1: Create a Netbeans Project and Account class
1. Create a Netbeans project called BankAccounts.
2. Create a Java file (class library type) called Account and set the package to coe318.lab3. Note: you are not provided with a template this time, you have to write it from scratch. Do not modify the automatically generated statement:
package coe318.lab3;
3. Determine your instance variables and implement the constructor.
4. Implement the other methods.
5. You are provided with a toString() method for the Account class (above) which you should copy and paste into your class.

Step 2: Test Account with MainAccount
1. Create a Java file (class library type) called MainAccount with package coe318.lab3 and copy and paste the provided source code from MainAccount.java.
2. You can run this main method either by invoking the Run file or changing the Netbeans configuration to specify the class containing the main method.
3. You should not continue until at least most of it works. Correct output from MainAccount
(Bob, 789, $0.00)
(Alice, 123, $100.00)
(Alice, 123, $85.00)
(Alice, 123, $85.00)
(Alice, 123, $85.00)
(Alice, 123, $35.00)
(Bob, 789, $300.00)
(Bob, 789, $200.00)

Step 3: Create the Bank Class
1. Create a Java file called Bank and copy/paste the provided template code.
2. Create a Java file MainBank which will be used to test your code. Copy the provided MainBank.java code into this file. (Reset the main method in the Netbeans configuration to make this your main class)
3. Fix the methods until it works.

Correct output from MainBank
Toronto Dominion: 0 of 3 accounts open Toronto Dominion: 1 of 3 accounts open
(Charles, 234, $200.00) td has account # 456: true
Toronto Dominion: 2 of 3 accounts open (Charles, 234, $200.00)
(Dora, 456, $300.00)
Bank of Montreal: 1 of 5 accounts open (Edward, 456, $400.00)
Step 4: Submit your lab
Please zip up your NetBeans project containing all source files and submit to the respective assignment folder on D2L.