Implementing the Payment App in Java
To implement the payment app in Java, we'll start by creating the main class for our app:
1public class PaymentApp {
2 public static void main(String[] args) {
3 // Code for the payment app
4 }
5}In the above code, we define the PaymentApp class with a main method as the entry point of our app.
Now let's create a class to represent the payment transaction:
1public class PaymentTransaction {
2 private String transactionId;
3 private double amount;
4 private PaymentMethod paymentMethod;
5
6 public PaymentTransaction(String transactionId, double amount, PaymentMethod paymentMethod) {
7 this.transactionId = transactionId;
8 this.amount = amount;
9 this.paymentMethod = paymentMethod;
10 }
11
12 public void processPayment() {
13 paymentMethod.processPayment(amount);
14 }
15
16 // Getters and setters
17}In the above code, the PaymentTransaction class represents a single payment transaction with properties like transaction ID, amount, and the selected payment method. The processPayment method is responsible for processing the payment through the chosen payment method.
Next, let's create an interface for the payment methods:
1public interface PaymentMethod {
2 void processPayment(double amount);
3}The PaymentMethod interface defines a contract for processing payments. Each payment method class will implement this interface and provide its own implementation logic.
Let's create a concrete implementation of the PaymentMethod interface for credit card payments:
1public class CreditCardPayment implements PaymentMethod {
2 private String cardNumber;
3 private String cvv;
4 private String expirationDate;
5
6 public CreditCardPayment(String cardNumber, String cvv, String expirationDate) {
7 this.cardNumber = cardNumber;
8 this.cvv = cvv;
9 this.expirationDate = expirationDate;
10 }
11
12 @Override
13 public void processPayment(double amount) {
14 // Logic for processing credit card payment
15 System.out.println("Processing credit card payment of $" + amount);
16 }
17
18 // Getters and setters
19}The CreditCardPayment class is a concrete implementation of the PaymentMethod interface. It has additional properties like card number, CVV, and expiration date, and provides its own implementation logic for processing credit card payments.
Similarly, let's create classes for other payment methods like bank transfer and mobile wallet:
1public class BankTransferPayment implements PaymentMethod {
2 private String accountNumber;
3 private String routingNumber;
4
5 public BankTransferPayment(String accountNumber, String routingNumber) {
6 this.accountNumber = accountNumber;
7 this.routingNumber = routingNumber;
8 }
9
10 @Override
11 public void processPayment(double amount) {
12 // Logic for processing bank transfer payment
13 System.out.println("Processing bank transfer payment of $" + amount);
14 }
15
16 // Getters and setters
17}
18
19public class MobileWalletPayment implements PaymentMethod {
20 private String walletId;
21 private String passcode;
22
23 public MobileWalletPayment(String walletId, String passcode) {
24 this.walletId = walletId;
25 this.passcode = passcode;
26 }
27
28 @Override
29 public void processPayment(double amount) {
30 // Logic for processing mobile wallet payment
31 System.out.println("Processing mobile wallet payment of $" + amount);
32 }
33
34 // Getters and setters
35}The BankTransferPayment and MobileWalletPayment classes provide their own implementation logic for processing bank transfer and mobile wallet payments, respectively.
Finally, let's put everything together in the main method of the PaymentApp class:
1public class PaymentApp {
2 public static void main(String[] args) {
3 // Create a payment transaction
4 PaymentTransaction transaction = new PaymentTransaction("123456", 100.0, new CreditCardPayment("1234567890", "123", "12/24"));
5
6 // Process the payment
7 transaction.processPayment();
8 }
9}In the above code, we create a PaymentTransaction object with a transaction ID, amount, and a CreditCardPayment instance as the selected payment method. We then call the processPayment method to initiate the payment processing using the chosen payment method. Running this code will output the message "Processing credit card payment of $100.0" to the console.
xxxxxxxxxx// Running this code will output the message "Processing credit card payment of $100.0" to the console.// Implementing the Payment App in Java// Let's start by creating the main class for our payment app:public class PaymentApp { public static void main(String[] args) { // Code for the payment app }}// In the above code, we define the `PaymentApp` class with a `main` method as the entry point of our app.// Now let's create a class to represent the payment transaction:public class PaymentTransaction { private String transactionId; private double amount; private PaymentMethod paymentMethod; public PaymentTransaction(String transactionId, double amount, PaymentMethod paymentMethod) { this.transactionId = transactionId; this.amount = amount; this.paymentMethod = paymentMethod; } public void processPayment() { paymentMethod.processPayment(amount); } // Getters and setters