Library Management System

A comprehensive library management system built with Java, featuring a JavaFX desktop client and a Socket-based server. The system provides complete book management, borrowing operations, user management, AI-powered recommendations, and real-time chat functionality.

Features

• Book Management: Add, update, delete, and search books with ISBN, title, author, category
• Borrowing System: Borrow and return books with automatic due date tracking
• User Management: Support for both regular users and administrators
• AI Recommendations: Intelligent book recommendations based on user preferences and reading history
• Real-time Chat: User-to-user messaging system
• Fine Management: Automatic fine calculation with configurable rate tiers
• Statistics Dashboard: Comprehensive statistics for administrators
• Trending Books: Display popular books based on borrowing frequency

Prerequisites

• Java: JDK 17 or higher
• Maven: 3.6 or higher
• PostgreSQL: 12 or higher
• pgvector Extension (optional): For enhanced AI recommendation features

Installation

1. Database Setup

1. Install PostgreSQL and create a database:

CREATE DATABASE library_db;

2. Execute the database schema:

psql -U postgres -d library_db -f database/schema.sql

3. Initialize admin user (optional):

psql -U postgres -d library_db -f database/init_admin.sql

4. Import demo data (optional):

psql -U postgres -d library_db -f database/import_demo_data.sql

2. Configuration

Edit server/src/main/resources/application.properties to configure database connection:

# Database Configuration
db.url=jdbc:postgresql://localhost:5432/library_db
db.username=postgres
db.password=your_password
db.pool.size.minimum=5
db.pool.size.maximum=20

# Server Configuration
server.port=9090
server.threadPoolSize=20

3. Build Project

mvn clean compile

Or use the provided batch script (Windows):

完整部署.bat

Usage

Starting the Server

Option 1: Using batch script (Windows)

start-server.bat

Option 2: Using Maven

mvn -pl server compile exec:java -Dexec.mainClass="com.library.server.ServerMain" -Dexec.args="9090"

Option 3: Using command line arguments

java -cp target/classes com.library.server.ServerMain [port] [threadPoolSize]

The server will start on port 9090 by default (or the port specified in application.properties).

Starting the Client

Option 1: Using batch script (Windows)

start-client.bat

Option 2: Using Maven

mvn -pl client compile javafx:run

Default Accounts

After running init_admin.sql, you can login with:

• Admin: username and password as configured in the SQL script
• Demo Users: Use create_demo_users.sql to create test accounts

User Operations

Regular Users can:

• Search and browse books
• Borrow and return books
• View borrowing history
• Receive AI-powered book recommendations
• Chat with other users
• View personal fines

Administrators can:

• Manage books (add, update, delete, import from CSV)
• View all borrowing records
• Manage users (freeze/unfreeze accounts)
• Configure fine rate tiers
• View system statistics
• Send reminders to users
• Manage all user fines

Project Structure

library-system/
├── client/                 # JavaFX client application
│   ├── src/main/java/     # Client source code
│   └── src/main/resources/ # UI resources (CSS, images)
├── server/                 # Socket server application
│   ├── src/main/java/     # Server source code
│   └── src/main/resources/ # Configuration files
├── common/                 # Shared code between client and server
│   └── src/main/java/     # Common protocols and utilities
├── database/               # SQL scripts
│   ├── schema.sql         # Main database schema
│   ├── init_admin.sql     # Admin user initialization
│   └── *.sql              # Additional migration scripts
└── pom.xml                 # Maven parent POM

Technical Details

Architecture

• Client-Server Architecture: Socket-based communication using TCP
• Protocol: Custom JSON-based protocol for request/response
• Database: PostgreSQL with connection pooling (HikariCP)
• UI Framework: JavaFX 17
• Build Tool: Maven 3.x

Technology Stack

• Backend:

  • Java 17
  • PostgreSQL 12+
  • HikariCP (Connection Pooling)
  • Jackson (JSON Processing)
  • SLF4J + Logback (Logging)

• Frontend:

  • JavaFX 17
  • CSS for styling

• AI/ML Features:

  • Vector embeddings for book recommendations
  • Graph-based recommendation algorithms
  • pgvector extension support (optional)

Key Components

1. Protocol Layer (common/protocol/):

   • OpCode: Operation codes for all system operations
   • Request/Response: JSON-based communication protocol
   • ErrorCode: Standardized error handling

2. Server Services (server/service/):

   • UserService: User authentication and management
   • BookService: Book CRUD operations
   • BorrowService: Borrowing and returning logic
   • AIRecommendService: AI-powered recommendations
   • ChatService: Real-time messaging
   • FineService: Fine calculation and management

3. Data Access Layer (server/dao/):

   • DAO pattern for database operations
   • Connection pooling with HikariCP
   • Prepared statements for SQL injection prevention

4. Client Views (client/view/):

   • LoginView: User authentication
   • UserHomeView: Regular user dashboard
   • AdminHomeView: Administrator dashboard
   • ChatView: Messaging interface
   • ReaderDashboardView: Reading recommendations

Database Schema

• users: User accounts with roles (USER/ADMIN) and status (ACTIVE/FROZEN)
• books: Book information with inventory tracking
• borrow_records: Borrowing history and status
• messages: User-to-user chat messages
• book_embeddings: Vector embeddings for AI recommendations (optional)
• fine_rate_config: Configurable fine rate tiers

Security Features

• Password hashing (stored as hash, never plain text)
• SQL injection prevention (PreparedStatement)
• User role-based access control
• Account freeze/unfreeze functionality

Performance Optimizations

• Database connection pooling (HikariCP)
• Indexed database queries
• Thread pool for concurrent client connections
• Efficient JSON serialization (Jackson)

Development

Building from Source

# Clean and compile all modules
mvn clean compile

# Package as JAR files
mvn clean package

# Run tests
mvn test

Running Tests

mvn test

Code Style

• Follow Java naming conventions
• Use meaningful variable and method names
• Add JavaDoc comments for public APIs
• Maintain consistent indentation (4 spaces)

Troubleshooting

Server won't start

1. Check if port 9090 is already in use:

netstat -ano | findstr :9090

2. Verify database connection settings in application.properties

3. Ensure PostgreSQL is running and database exists

Client can't connect to server

1. Verify server is running and listening on the correct port
2. Check firewall settings
3. Verify server address in client code (default: localhost:9090)

Database connection errors

1. Verify PostgreSQL is running
2. Check database credentials in application.properties
3. Ensure database library_db exists
4. Verify user has proper permissions

Encoding issues

The project uses UTF-8 encoding. If you encounter encoding problems:

• Ensure your terminal supports UTF-8
• Check file encoding settings in your IDE
• Windows batch scripts use chcp 65001 to set UTF-8

License

This project is for educational purposes.

Contributing

1. Fork the repository
2. Create a feature branch
3. Make your changes
4. Submit a pull request

Contact

For questions or issues, please open an issue on GitHub.