code-index-mcp

# 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 ```bash mvn clean compile ``` ### Run ```bash mvn exec:java -Dexec.mainClass="com.example.usermanagement.Main" ``` ### Test ```bash mvn test ``` ### Package ```bash mvn package ``` ## Usage ### Creating Users ```java 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 ```java // 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 ```java // 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.