Library Management System

A Spring Boot application for managing library operations including books, users, and borrowing records.

Technical Stack

• Java 17
• Spring Boot 2.5.4
• Spring Data JPA
• Spring Security
• PostgreSQL
• Maven
• JUnit & Mockito

Project Structure

Core Packages

Controllers (src/main/java/com/avan/libraryapp1/controller/)

• BookController - Book CRUD operations and borrowing
• UserController - User management
• BorrowRecordController - Borrowing history tracking

Services (src/main/java/com/avan/libraryapp1/services/)

• BookService - Business logic for book operations
• UserService - User management logic
• BorrowRecordService - Borrowing workflow management

Models (src/main/java/com/avan/libraryapp1/model/)

• Book - Book entity with validation
• User - User entity with role-based access
• BorrowRecord - Borrowing transaction records

Repositories (src/main/java/com/avan/libraryapp1/repository/)

• Spring Data JPA repositories for data persistence

Security (src/main/java/com/avan/libraryapp1/security/)

• Authentication and authorization configuration
• Custom user details service

DTOs (src/main/java/com/avan/libraryapp1/dto/)

• Data transfer objects with validation

Exception Handling (src/main/java/com/avan/libraryapp1/exceptions/)

• Global exception handler with custom exceptions

Key Features

• Complete CRUD operations for books and users
• Book borrowing and return system
• Role-based security authentication
• RESTful API endpoints
• Input validation and error handling
• PostgreSQL database integration

API Endpoints

Books

• GET /api/books - List all books
• GET /api/books/{id} - Get book by ID
• POST /api/books - Create new book
• PUT /api/books/{id} - Update book
• DELETE /api/books/{id} - Delete book
• POST /api/books/{bookId}/borrow/{userId} - Borrow book
• POST /api/books/{bookId}/return - Return book

Users

• GET /api/users - List all users
• GET /api/users/{id} - Get user by ID
• POST /api/users - Create new user
• PUT /api/users/{id} - Update user
• DELETE /api/users/{id} - Delete user

Borrow Records

• GET /api/borrow-records - List all borrow records
• GET /api/borrow-records/{id} - Get borrow record by ID
• POST /api/borrow-records - Create borrow record
• PUT /api/borrow-records/{id} - Update borrow record
• DELETE /api/borrow-records/{id} - Delete borrow record

Testing

The project includes comprehensive unit tests using JUnit and Mockito.

Test Structure:

• Unit tests: src/test/java/com/avan/libraryapp1/unittests/
• Integration tests: src/test/java/com/avan/libraryapp1/integrationtests/

Run tests:

mvn test

Current test coverage includes:

• BookService unit tests with mocking
• Application context loading tests
• Exception handling validation

Setup and Installation

Prerequisites

• Java 17 or higher
• Maven 3.6+
• PostgreSQL 12+

Database Configuration

Update src/main/resources/application.yml:

spring:
  datasource:
    url: jdbc:postgresql://localhost:5432/LibraryManagement
    username: your_username
    password: your_password

Build and Run

# Clone repository
git clone [repository-url]

# Build application
mvn clean install

# Run application
mvn spring-boot:run

The application will start on http://localhost:8080

Security

• Form-based authentication
• BCrypt password encoding
• Role-based access control
• Session management with CSRF protection

Development Philosophy

I've deliberately chosen trunk-based development over TDD for this project. While I respect TDD's place in enterprise environments and have extensive experience with it, I find compiler-driven development more efficient for rapid iteration. My preference is trunk-based workflow with rigorous code reviews as quality gates rather than extensive upfront test coverage. This approach delivers working software faster while maintaining quality through systematic review processes. I adapt to team methodologies as needed, but this represents my preferred development philosophy.

Database Schema

The application uses JPA with automatic DDL generation. Tables are created automatically on startup:

• books - Book information and availability
• users - User accounts and roles
• borrow_record - Borrowing transaction history