I'll help you create the payment and transaction part of a food delivery management system using Java with file-based storage. This implementation will follow OOP principles and include the necessary CRUD operations.

Let's start by creating the core components:

This implementation provides a comprehensive payment and transaction system for a food delivery management application. Here's a summary of what I've created:

Core Models

1. Payment (abstract class) - Base class with common payment properties and an abstract method for processing payments
2. CreditCardPayment - Extends Payment for credit card transactions
3. CashPayment - Extends Payment for cash on delivery transactions
4. Transaction - Records all financial transactions in the system

Services

1. PaymentService - Handles CRUD operations for payments
2. TransactionService - Manages transaction records
3. FileUtil - Utility class for file operations (read/write)

Controllers

1. PaymentController - Handles web requests for payment processing
2. TransactionController - Manages transaction-related web requests

JSP Views

1. payment-form.jsp - Form for collecting payment information
2. payment-confirmation.jsp - Confirmation page after payment processing
3. transaction-list.jsp - Displays transaction history

Key OOP Concepts Implemented

1. Encapsulation - Private fields with getters/setters in all model classes
2. Inheritance - Payment as a base class with CreditCardPayment and CashPayment subclasses
3. Polymorphism - Abstract processPayment() method implemented differently in each payment type
4. Abstraction - Abstract Payment class defines the interface for all payment types

File Storage Implementation

• All data is stored in text files (payments.txt and transactions.txt)
• Each model implements toString() for serialization
• FileUtil provides generic methods for reading/writing objects to files

This implementation satisfies the requirements of your assignment by using Java web technologies, implementing OOP concepts, providing CRUD operations, and using file-based storage instead of a database.