Claude-Code-Workflow/reference/code-index-mcp-master/test/sample-projects/java/user-management/README.md

User Management System (Java)

A comprehensive user management system built in Java for testing Code Index MCP's analysis capabilities.

Features

• User Management: Create, update, delete, and search users
• Authentication: BCrypt password hashing and verification
• Authorization: Role-based access control (Admin, User, Guest)
• Data Validation: Input validation and sanitization
• Export/Import: JSON and CSV export capabilities
• Persistence: File-based storage with JSON serialization
• Logging: SLF4J logging with Logback

Project Structure

src/main/java/com/example/usermanagement/
├── models/
│   ├── Person.java            # Base person model
│   ├── User.java              # User model with auth features
│   ├── UserRole.java          # User role enumeration
│   └── UserStatus.java        # User status enumeration
├── services/
│   └── UserManager.java       # User management service
├── utils/
│   ├── ValidationUtils.java   # Validation utilities
│   ├── UserNotFoundException.java    # Custom exception
│   └── DuplicateUserException.java   # Custom exception
└── Main.java                  # Main demo application

Technologies Used

• Java 11: Modern Java features and APIs
• Jackson: JSON processing and serialization
• BCrypt: Secure password hashing
• Apache Commons: Utility libraries (Lang3, CSV)
• SLF4J + Logback: Logging framework
• Maven: Build and dependency management
• JUnit 5: Testing framework

Build and Run

Prerequisites

• Java 11 or higher
• Maven 3.6+

Build

mvn clean compile

Run

mvn exec:java -Dexec.mainClass="com.example.usermanagement.Main"

Test

mvn test

Package

mvn package

Usage

Creating Users

UserManager userManager = new UserManager();

// Create a basic user
User user = userManager.createUser("John Doe", 30, "john_doe", "john@example.com");
user.setPassword("SecurePass123!");

// Create an admin user
User admin = userManager.createUser("Jane Smith", 35, "jane_admin", 
                                  "jane@example.com", UserRole.ADMIN);
admin.setPassword("AdminPass123!");
admin.addPermission("user_management");

User Authentication

// Verify password
boolean isValid = user.verifyPassword("SecurePass123!");

// Login
if (user.login()) {
    System.out.println("Login successful!");
    System.out.println("Last login: " + user.getLastLogin());
}

User Management

// Search users
List<User> results = userManager.searchUsers("john");

// Filter users
List<User> activeUsers = userManager.getActiveUsers();
List<User> adminUsers = userManager.getUsersByRole(UserRole.ADMIN);
List<User> olderUsers = userManager.getUsersOlderThan(25);

// Update user
Map<String, Object> updates = Map.of("age", 31, "email", "newemail@example.com");
userManager.updateUser("john_doe", updates);

// Export users
String jsonData = userManager.exportUsers("json");
String csvData = userManager.exportUsers("csv");

Testing Features

This project tests the following Java language features:

Core Language Features

• Classes and Inheritance: Person and User class hierarchy
• Enums: UserRole and UserStatus with methods
• Interfaces: Custom exceptions and validation
• Generics: Collections with type safety
• Annotations: Jackson JSON annotations
• Exception Handling: Custom exceptions and try-catch blocks

Modern Java Features

• Streams API: Filtering, mapping, and collecting
• Lambda Expressions: Functional programming
• Method References: Stream operations
• Optional: Null-safe operations
• Time API: LocalDateTime usage

Advanced Features

• Concurrent Collections: ConcurrentHashMap
• Reflection: Jackson serialization
• File I/O: NIO.2 Path and Files
• Logging: SLF4J with parameterized messages
• Validation: Input validation and sanitization

Framework Integration

• Maven: Build lifecycle and dependency management
• Jackson: JSON serialization/deserialization
• BCrypt: Password hashing
• Apache Commons: Utility libraries
• SLF4J: Structured logging

Design Patterns

• Builder Pattern: Object construction
• Factory Pattern: User creation
• Repository Pattern: Data access
• Service Layer: Business logic separation

Dependencies

Core Dependencies

• Jackson Databind: JSON processing
• Jackson JSR310: Java 8 time support
• BCrypt: Password hashing
• Apache Commons Lang3: Utilities
• Apache Commons CSV: CSV processing

Logging

• SLF4J API: Logging facade
• Logback Classic: Logging implementation

Testing

• JUnit 5: Testing framework
• Mockito: Mocking framework

License

MIT License - This is a sample project for testing purposes.