📚 Bookstore RESTful API – JAX-RS Coursework

🔍 Overview

This project implements a RESTful backend for a Bookstore application using Java JAX-RS. It simulates an e-commerce environment with CRUD functionality for books, authors, customers, shopping carts, and orders.

The project is developed using JAX-RS (Jersey), with JSON as the data exchange format and Postman for API testing. All data is stored in-memory using standard Java collections (ArrayList, HashMap)—no external databases or frameworks are used as per coursework regulations.

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🎯 Coursework Objectives

• Apply RESTful principles and JAX-RS to design scalable APIs.
• Implement resource classes using standard HTTP methods (GET, POST, PUT, DELETE).
• Handle request and response bodies in JSON.
• Implement clean exception handling using ExceptionMapper.
• Model e-commerce entities such as books, authors, customers, shopping carts, and orders.
• Execute and document API tests using Postman.

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🛠️ Tech Stack

Technology	Purpose
Java (JDK 17)	Backend logic & in-memory data models
JAX-RS (Jersey)	REST API implementation
JSON	Request & Response payloads
Postman	API testing
ArrayList / HashMap	In-memory storage (No DB allowed)

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🧩 Resource Classes & Endpoints

🔹 BookResource (/books)

• POST /books – Add a new book
• GET /books – Get all books
• GET /books/{id} – Get book by ID
• PUT /books/{id} – Update a book
• DELETE /books/{id} – Delete a book

🔹 AuthorResource (/authors)

• POST /authors
• GET /authors
• GET /authors/{id}
• PUT /authors/{id}
• DELETE /authors/{id}
• GET /authors/{id}/books – List all books by author

🔹 CustomerResource (/customers)

• POST /customers
• GET /customers
• GET /customers/{id}
• PUT /customers/{id}
• DELETE /customers/{id}

🔹 CartResource (/customers/{customerId}/cart)

• POST /customers/{customerId}/cart/items
• GET /customers/{customerId}/cart
• PUT /customers/{customerId}/cart/items/{bookId}
• DELETE /customers/{customerId}/cart/items/{bookId}

🔹 OrderResource (/customers/{customerId}/orders)

• POST /customers/{customerId}/orders
• GET /customers/{customerId}/orders
• GET /customers/{customerId}/orders/{orderId}

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🧱 Data Models

• Book: title, authorId, ISBN, publicationYear, price, stock
• Author: id, name, biography
• Customer: id, name, email, password
• Cart: List of BookItems (bookId, quantity)
• Order: Order summary from cart items

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🚫 Exception Handling

Handled using custom exceptions and ExceptionMapper for proper REST responses:

Exception	Mapped Status	Trigger Scenario
BookNotFoundException	404 Not Found	Non-existent book ID
AuthorNotFoundException	404 Not Found	Invalid author ID
CustomerNotFoundException	404 Not Found	Missing customer
InvalidInputException	400 Bad Request	Invalid payload
OutOfStockException	400 Bad Request	Not enough book stock
CartNotFoundException	404 Not Found	Empty cart access

All error responses return JSON objects:

{
  "error": "Author Not Found",
  "message": "Author with ID 999 does not exist."
}