Pages

Wednesday, 26 October 2016

Chapter 11 Exercise 3, Introduction to Java Programming, Tenth Edition Y. Daniel LiangY.

11.3 (Subclasses of Account) In Programming Exercise 9.7, the Account class was
defined to model a bank account. An account has the properties account number,
balance, annual interest rate, and date created, and methods to deposit and withdraw
funds. Create two subclasses for checking and saving accounts. A checking
account has an overdraft limit, but a savings account cannot be overdrawn.
Draw the UML diagram for the classes and then implement them. Write
a test program that creates objects of Account, SavingsAccount, and
CheckingAccount and invokes their toString() methods.

import java.util.ArrayList;
import java.util.Date;

public class Account {

    protected String mName;
    protected int mId;
    protected double mBalance;
    protected double mAnnualInterestRate; // AnnualInterestRate is percentage.
    protected Date mDateCreated;
    protected ArrayList<Transaction> mTransactions;


    public Account() {
        mDateCreated = new Date();
        mTransactions = new ArrayList<>();
    }

    public Account(int id, double balance) {
        this();
        mId = id;
        mBalance = balance;
    }

    public Account(String name, int id, double balance) {
        this(id, balance);
        mName = name;

    }

    public int getId() {
        return mId;
    }

    public void setId(int id) {
        mId = id;
    }

    public double getBalance() {
        return mBalance;
    }

    public void setBalance(double balance) {
        mBalance = balance;
    }

    public double getAnnualInterestRate() {
        return mAnnualInterestRate;
    }

    public void setAnnualInterestRate(double annualInterestRate) {
        mAnnualInterestRate = annualInterestRate;
    }

    public Date getDateCreated() {
        return mDateCreated;
    }

    public double getMonthlyInterestRate() {
        return mBalance * (mAnnualInterestRate / 12) / 100;
    }

    public void withdraw(double amount) {
        mTransactions.add(new Transaction('W', amount, mBalance, "withdraw"));
        mBalance -= amount;
    }

    public void deposit(double amount) {
        mTransactions.add(new Transaction('D', amount, mBalance, "deposit"));
        mBalance += amount;
    }

    @Override
    public String toString() {
        return "Account name: " + mName + "\n" + "Interest rate: " + mAnnualInterestRate + "\n" + mTransactions;
    }

    public ArrayList<Transaction> getTransactions() {
        return new ArrayList<>(mTransactions);
    }

}
public class CheckingAccount extends Account {

    protected double OVERDRAFT_LIMIT = -100;

    public CheckingAccount(int id, double balance) {
        super(id, balance);
    }

    @Override
    public void withdraw(double amount) {
        if (mBalance - amount >= OVERDRAFT_LIMIT) {
            super.withdraw(amount);
        }
    }

    @Override
    public String toString() {
        return "CheckingAccount{"+
                "mBalance=" + mBalance +
                '}';
    }
}
public class SavingsAccount extends Account {

    protected double OVERDRAFT_LIMIT = 0;

    public SavingsAccount(int id, double balance) {
        super(id, balance);
    }

    @Override
    public void withdraw(double amount) {
        if (mBalance - amount >= OVERDRAFT_LIMIT) {
            super.withdraw(amount);
        }
    }

    @Override
    public String toString() {
        return "SavingsAccount{" +
                "mBalance=" + mBalance +
                '}';
    }
}
public class Exercise_03 {

    public static void main(String[] args) {

        Account account = new Account(111, 200);
        CheckingAccount checkingAccount = new CheckingAccount(112, 250);
        SavingsAccount savingsAccount = new SavingsAccount(113, 300);

        System.out.println(account);
        System.out.println(checkingAccount);
        System.out.println(savingsAccount);
    }

}

4 comments: