labexercises2324/week23.java

import java.util.Scanner;

class Person {
    private int age;
    private String name;

    public int getAge() {
        return age;
    }
    public void setAge(int age) {
        this.age = age;
    }
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }

    public String toString() {
        return this.getName();
    }

}

class DemoPerson {
    public static void main(String[] args) {

        System.out.println(String.format("Would you like to meet a person?"));
        Person simon = new Person();
        simon.setAge(38);
        simon.setName("Simon");
        System.out.println(String.format("Their name is %s and their age is %d",
                                         simon.getName(), simon.getAge()));

        String newName = getUserInput("What shall we change their name to?");
        simon.setName(newName);


        System.out.println(String.format("Their name is now %s, but their age remains %d",
                                         simon, simon.getAge())); // uses toString()
    }

    /** A simple wrapper to get some user input easily
     * @param prompt What to prompt user for
     * @return User's input
     */
    public static String getUserInput(String prompt) {
        Scanner userInput = new Scanner(System.in);
        System.out.println(String.format("%s", prompt));

        if (userInput.hasNextLine()) {
            return userInput.nextLine();
        } else {
            return "";
        }
    }
}

class BankAccount {
    private Person person;
    private int accountNumber;
    private double balance;

    private static int nextAccountNumber = 0;

    public BankAccount(Person person) {
        this.person = person;
        this.balance = 0.0;
        this.accountNumber = nextAccountNumber;
        nextAccountNumber++;
    }

    @Override
    public String toString() {
        return "BankAccount [person=" + person + ", accountNumber=" + accountNumber + ", balance=" + balance + "]";
    }

    public Person getPerson() {
        return person;
    }

    public int getAccountNumber() {
        return accountNumber;
    }

    public double getBalance() {
        return balance;
    }

    public void setBalance(double balance) {
        this.balance = balance;
    }

    public void deposit (double amount) {
        this.balance += amount;
    }

    public void withdraw(double amount) {
        // No overdraft facilities here!
        // wait, reading ahead, there are...
        // if (amount <= balance) {
            this.balance -= amount;
            //}
    }

    /** Transfer funds out of the account to another {@link BankAccount}
     * @param amount Amount to transfer
     * @param recipient The lucky beneficiary
     */
    public void transferFunds(double amount, BankAccount recipient) {
        this.withdraw(amount);
        recipient.deposit(amount);
    }
}

/**
 * Exercise 2.4 & 2.6 - create two bank account objects and print their account
 * numbers, which should be 0 and 1.
 *
 * Then 2.8 & 2.9 where we change it to use Person
 */
class DemoBankAccount {
    public static void main(String[] args) {
        Person jerry = new Person();
        jerry.setName("Jerry");
        Person margo = new Person();
        margo.setName("Margo");

        BankAccount account1 = new BankAccount(jerry);
        BankAccount account2 = new BankAccount(margo);

        System.out.println(String.format("%s's account number: %d", account1.getPerson(), account1.getAccountNumber()));
        System.out.println(String.format("%s's account number: %d", account2.getPerson(), account2.getAccountNumber()));

        System.out.println(String.format("Jerry will deposit £10, Margo will deposit £25"));
        account1.deposit(10.00);
        account2.deposit(25.00);
        System.out.println(String.format("Accounts:\n\t%s\n\t%s\n", account1, account2));

        System.out.println(String.format("Jerry goes to the pub and needs some cash for that. Margo goes to buy new garden furniture."));
        account1.withdraw(5.00);
        account2.withdraw(15.00);
        System.out.println(String.format("Accounts:\n\t%s\n\t%s", account1, account2));

        System.out.println(".".repeat(80));
        System.out.println(String.format("Now we're going to set up two accounts for the one person.\n"));
        Person neighbour = new Person();
        neighbour.setName("Tom");
        BankAccount account3 = new BankAccount(neighbour);
        BankAccount account4 = new BankAccount(neighbour);
        System.out.println(String.format("Accounts:\n\t%s\n\t%s\n", account3, account4));

        System.out.println(String.format("%s deposits some money in each.", neighbour));
        account3.deposit(12.50);
        account4.deposit(3.33);

        System.out.println(String.format("Actually wait, the account wasn't set up in %s's name...", neighbour));
        neighbour.setName("Barbara");
        System.out.println(String.format("Accounts:\n\t%s\n\t%s\n", account3, account4));

        System.out.println(".".repeat(80));
        System.out.println(String.format("To help %s buy a new goat, %s lends them some money.",
                                         neighbour, margo));
        account2.transferFunds(10.00, account3);
        System.out.println(String.format("Accounts:\n\t%s\n\t%s\n\t%s\n", account2, account3, account4));
    }
}

class Student extends Person {
    private double gpa;

    public double getGpa() {
        return gpa;
    }

    public void setGpa(double gpa) {
        this.gpa = gpa;
    }

    @Override
    public String toString() {
        return "Student [gpa=" + gpa + ", name=" + this.getName() + "]";
        // Ah, we can't access private members of parent classes from the child class
    }
}

class Lecturer extends Person {
    private double salary;

    public double getSalary() {
        return salary;
    }

    public void setSalary(double salary) {
        this.salary = salary;
    }

    @Override
    public String toString() {
        return "Lecturer [salary=" + salary + ", name=" + this.getName() + "]";
    }
}

/**
 * Exercise 3.1, 3.2, 3.3 - implement Student and Lcturer classes
 *
 */
class DemoStudentLecturer {
    public static void main(String[] args) {
        Student adrian = new Student();
        adrian.setName("Adrian");
        adrian.setGpa(3.5);

        Lecturer trefusis = new Lecturer();
        trefusis.setName("Donald");
        trefusis.setSalary(24199);

        System.out.println(String.format("At a particular Oxbridge college, we have two people"));
        System.out.println(String.format("%s\t\t&\t\t%s", adrian, trefusis));
    }
}

class SavingsAccount extends BankAccount {
    @Override
    public String toString() {
        return "SavingsAccount [interestRate=" + interestRate + "]";
    }

    private double interestRate;

    /** Set up savings account for the thrifty
     * @param person A {@link Person} object
     * @param interestRate Expressed as %
     */
    public SavingsAccount(Person person, double interestRate) {
        super(person);
        this.interestRate = interestRate;
    }

    @Override
    public void withdraw(double amount) {
        if (amount <= this.getBalance()) {
            this.setBalance(this.getBalance() - amount);
        }
    }

    public void addInterest() {
        this.setBalance(this.getBalance() + (this.getBalance() * (this.interestRate / 100)));
    }
}

class DemoSavingsAccount {
    public static void main(String[] args) {
        Person hotblack = new Person();
        hotblack.setName("Hotblack Desiato");

        SavingsAccount savings1 = new SavingsAccount(hotblack, 6);
        savings1.deposit(100.00);

        System.out.println(String.format("%s plays a gig with DA and gets paid", hotblack));
        System.out.println(String.format("Account:\n\t%s", savings1));
        System.out.println(".".repeat(80));

        System.out.println(
                String.format("%s has a PGGB and tries to take out £200 to cover the cleanup expenses!", hotblack));
        savings1.withdraw(200.00);
        System.out.println(String.format("Account:\n\t%s", savings1));
        System.out.println(String.format("Fortunately (?), his bank blocks the transaction."));
        System.out.println(".".repeat(80));

        System.out.println(String.format("After 1 year, %s's account accrues interest!", hotblack));
        savings1.addInterest();
        System.out.println(String.format("Account:\n\t%s", savings1));
        System.out.println(String.format("%s wonders what it would be like after 1000 years...", hotblack));
        System.out.println(".".repeat(80));

        for (int i=0; i < 999; i++) {
            savings1.addInterest();
            if (i % 20 == 0) {
                System.out.printf("%.2f\t", savings1.getBalance());
            }
        }
        System.out.println(String.format("...finally, after 1000 years spent dead for tax purposes, %s checks his account", hotblack));
        System.out.println(String.format("Account:\n\t%s", savings1));

    }
}

class PolymorphismTest {
    public static void main(String[] args) {
        Person telemachus = new Person();
        telemachus.setName("Τηλέμαχος");
        BankAccount b = new SavingsAccount(telemachus, 10);

        System.out.println(String.format("%s", b));
    }
}