GitHub - Saiganesh224212/Advanced_Java_Lab: This repository contains all assignments, projects, and Java code for the Advanced Java Lab course, following SOLID principles, design patterns, and coding practices.

This folder contains all the assignments for the Advanced Java Lab (UCSH-605) course, focusing on SOLID principles, Object-Oriented Design, and Java Coding practices.

📜 List of Assignments

Assignment	Description	Topics Covered
Assignment 1	Refactor a Poorly Designed Code (Apply SRP & OCP)	Single Responsibility Principle (SRP), Open/Closed Principle (OCP)
Assignment 2	Implement Liskov Substitution Principle (LSP)	Liskov Substitution Principle (LSP), Class Hierarchy Design
Assignment 3	Payment Processing System (Applying All SOLID Principles)	SOLID Principles, Interface Segregation, Dependency Inversion
Assignment 4	Chat App using Socket Programming in Java	1) One-to-One 2) One-to-Many

🔹 Assignment 1: Refactor a Poorly Designed Code (SRP & OCP)

📌 Problem Statement

The given Java code violates SRP (Single Responsibility Principle) and OCP (Open/Closed Principle).
Refactor the code to:

Separate concerns properly (SRP)
Make it extensible for new storage types without modifying the base class (OCP)

📌 Files

easy1.java Original code violating SOLID principles → Refactored version following SRP & OCP.

📌 Topics Covered

✅ Single Responsibility Principle (SRP) – Ensure each class has a single responsibility.
✅ Open/Closed Principle (OCP) – Allow extension without modifying existing code.

🔹 Assignment 2: Implement Liskov Substitution Principle (LSP)

📌 Problem Statement

A Penguin class extends Bird, but Bird has a fly() method. This violates LSP because not all birds can fly.

📌 Task

Identify the issue in the hierarchy.
Refactor the design to follow LSP.
Ensure subclasses can replace the base class without breaking behavior.

📌 Files

easy2.java
- Before Refactoring → Penguin inherits fly(), violating LSP.
- After Refactoring → Introduces Bird as an abstract class and CanFly interface.

📌 Topics Covered

✅ Liskov Substitution Principle (LSP) – Subclasses must be replaceable without altering system correctness.
✅ Proper Class Hierarchy Design – Use abstraction to define capabilities correctly.

🔹 Assignment 3: Design a Payment Processing System (SOLID)

📌 Problem Statement

Create a scalable and maintainable payment processing system supporting:

Credit Card
PayPal
Google Pay

📌 Requirements

✅ Follow SOLID Principles
✅ Allow adding new payment methods without modifying existing code
✅ Use dependency injection for flexibility

📌 Class Structure

PaymentService (Interface)
   ├── CreditCardPayment (Implements PaymentService)
   ├── PayPalPayment (Implements PaymentService)
   ├── GooglePayPayment (Implements PaymentService)
PaymentProcessor
PaymentLogger
PaymentServiceManager
Main

📌 Files

diffass3.java Implements all SOLID principles in a payment system.

📌 Topics Covered

✅ Single Responsibility Principle (SRP) – Separate payment processing, logging, and transaction handling.
✅ Open/Closed Principle (OCP) – Allow new payment methods without modifying existing code.
✅ Liskov Substitution Principle (LSP) – Ensure each payment method behaves correctly as a PaymentService.
✅ Interface Segregation Principle (ISP) – Keep interfaces minimal and focused.
✅ Dependency Inversion Principle (DIP) – Depend on abstractions (PaymentService), not concrete implementations.

how_to_run: steps:

- step: Clone the repository
  command: |
    git clone https://github.com/Saiganesh224212/Advanced_Java_Lab.git

- step: Compile Java files
  commands:
    - javac easy1.java
    - javac easy2.java
    - javac diffass3.java

- step: Run Java programs
  commands:
    - java easy1
    - java easy2
    - java diffass3

GitHub - Saiganesh224212/Advanced_Java_Lab: This repository contains all assignments, projects, and Java code for the Advanced Java Lab course, following SOLID principles, design patterns, and coding practices.

📜 List of Assignments

🔹 Assignment 1: Refactor a Poorly Designed Code (SRP & OCP)

📌 Problem Statement

📌 Files

📌 Topics Covered

🔹 Assignment 2: Implement Liskov Substitution Principle (LSP)

📌 Problem Statement

📌 Task

📌 Files

📌 Topics Covered

🔹 Assignment 3: Design a Payment Processing System (SOLID)

📌 Problem Statement

📌 Requirements

📌 Class Structure

📌 Files

📌 Topics Covered

🔹 Assignment 4: Design a Chat App using Sockets in JAVA