Spring Boot Employee Management Project with JWT JPA Swagger Caching

https://github.com/Tedytobias/SpringBoot-Employeee-Management-Project/releases

A real-time project centered on core Spring Boot concepts. It covers CRUD operations, JPA, validation, security with JWT, exception handling, Swagger, and caching. It also includes advanced features like pagination, file uploads, Actuator, and microservices integration. The project is designed to be a practical blueprint for building robust, scalable employee management systems with Spring Boot.

Table of contents

• Overview
• Key features
• Tech stack
• How to run locally
• Project structure
• Core modules
• Data model
• Validation
• Security and authentication
• Exception handling
• API documentation
• Caching
• Pagination
• File upload and download
• Spring Actuator
• Microservices and integration
• Testing
• Logging and observability
• Deployment and packaging
• How to upgrade and release notes
• Contributing
• License

Overview This repository presents a complete, production-ready starter for a Spring Boot based employee management system. It demonstrates end-to-end behavior from the user interface to the data store and back. It uses an in-memory H2 database for simplicity during development, and it can be easily swapped for a persistent database. It highlights essential patterns you will need to build real-world backends, including:

• Create, read, update, delete (CRUD) operations on employee entities.
• Data validation to ensure data integrity and user-friendly error messages.
• JWT-based security to protect endpoints and control access.
• Comprehensive exception handling with consistent error responses.
• API documentation via Swagger UI for easy exploration and testing.
• Caching to improve performance and reduce load on the database.
• Pagination to handle large result sets efficiently.
• File uploads for profile pictures or documents.
• Spring Actuator for monitoring and health checks.
• Microservices friendly design to ease integration with other services.

Tech stack

• Java 11+ (or newer compatible with Spring Boot)
• Spring Boot 2.x/3.x (as appropriate for your environment)
• Spring Data JPA
• H2 in-memory database (for development)
• Bean Validation (javax.validation / jakarta.validation)
• Spring Security with JWT
• Swagger/OpenAPI (Swagger UI)
• Spring Cache (in-memory or compatible provider)
• Spring Actuator
• RESTful API design
• JUnit 5 for testing
• Lombok (optional) for boilerplate reduction
• Maven or Gradle as the build tool

How to run locally Prerequisites

• Java Development Kit (JDK) 11 or newer
• Maven 3.6+ or Gradle 6+ (depending on project config)
• An IDE of your choice (IntelliJ IDEA, Eclipse, VS Code, etc.)
• Optional: Docker if you want to run a database container for more realistic setups

Step-by-step guide

1. Clone the repository

• Use your preferred Git client to clone the repository to your local machine.

2. Install dependencies

• For Maven: mvn clean install
• For Gradle: ./gradlew build

3. Configure the application

• Open application.properties (or application.yml) and review:
  • Database settings (H2 by default for quick starts)
  • Security settings (JWT secret, token validity)
  • Cache configuration
  • Actuator endpoints

4. Run the application

• For Maven: mvn spring-boot:run
• For Gradle: ./gradlew bootRun

5. Access the API

• The API typically runs on http://localhost:8080
• Swagger UI is available at http://localhost:8080/swagger-ui.html (or the configured path)
• Actuator endpoints, such as health and metrics, are exposed under /actuator

6. Test endpoints

• Use Swagger UI to try out endpoints, or use curl/postman to interact with the API.

7. Explore the releases From the releases page, download the latest release package and run the included executable. The direct link to the releases page is available here for quick access: https://github.com/Tedytobias/SpringBoot-Employeee-Management-Project/releases

Project structure

• src/main/java: Core Java source code
  • com.example.employee: Domain model, repositories, services, controllers
  • com.example.employee.config: Security, caching, and general configuration
  • com.example.employee.controller: REST controllers for CRUD and ancillary endpoints
  • com.example.employee.service: Business logic
  • com.example.employee.dto: Data transfer objects for requests and responses
  • com.example.employee.exception: Custom exceptions and handler
  • com.example.employee.security: JWT utilities and security configuration
  • com.example.employee.util: Helpers and utilities
• src/main/resources: Configuration files, SQL scripts, and resources
  • application.properties: Core configuration
  • schema.sql and data.sql: Optional initial data
  • static assets: If you expose a UI, static resources can reside here
  • swagger configuration: OpenAPI/Swagger setup
• src/test: Unit and integration tests
  • user: Test suites for service and controller layers
  • integration: End-to-end tests using in-memory server
• pom.xml or build.gradle: Build configuration and dependencies
• README.md: This documentation

Core modules explained

• Domain model
  • Employee entity with fields like id, firstName, lastName, email, department, salary, hireDate, status, and avatarUrl.
  • Validation annotations ensure name formats, email structure, and non-null constraints.
• Data access
  • Spring Data JPA repositories provide CRUD operations with minimal boilerplate.
  • H2 database is used for development; swap to MySQL/PostgreSQL with minimal changes.
• Service layer
  • Encapsulates business logic for employee operations, validation, and data transformations.
  • Handles optimistic locking or versioning if needed to prevent concurrent update issues.
• Web layer
  • REST controllers expose endpoints for listing, creating, updating, and deleting employees.
  • Endpoints for additional actions like search, sorting, and filtering.
• Security
  • JWT-based authentication to secure endpoints.
  • Role-based access to sensitive operations.
  • Token generation on login and token refresh mechanisms.
• Validation
  • Bean validation ensures correct data on input.
  • Custom validators for business rules (e.g., unique email) can be added.
• Exception handling
  • Centralized exception handler returns uniform error payloads.
  • Distinguishes between client errors (4xx) and server errors (5xx).
• API documentation
  • Swagger UI provides interactive API docs out of the box.
  • OpenAPI annotations help keep docs in sync with code.
• Caching
  • Simple in-memory caching to speed up frequently called endpoints.
  • Cache eviction strategies keep data fresh.
• Pagination
  • Endpoints support page size and page number parameters.
  • Sorting and filtering options to refine results.
• File uploads
  • Endpoints support uploading avatar images or documents.
  • Uploaded files can be stored on disk or in a blob store.
• Actuator
  • Health, metrics, and info endpoints help monitor the app.
  • Custom health indicators can reflect business health as needed.
• Microservices integration
  • Design patterns and starter configurations for service discovery, API gateways, and inter-service communication.
  • Clear boundaries to ease the extraction of modules into independent services.

Data model highlights

• Employee
  • id: Long
  • firstName: String
  • lastName: String
  • email: String (unique)
  • department: String
  • salary: BigDecimal
  • hireDate: LocalDate
  • status: Enum (ACTIVE, INACTIVE, ON_LEAVE)
  • avatarUrl: String (URL or path to stored file)
• Additional entities
  • Department or Role if you want to expand the domain.
  • Audit fields for createdBy, createdAt, updatedBy, updatedAt.

Validation and data integrity

• Basic constraints
  • @NotNull, @NotBlank on required fields
  • @Email for email formatting
  • @Size for string length constraints
  • @PastOrPresent for dates where appropriate
• Business rules
  • Unique email constraint at the database level
  • Salary must be positive
  • Hire date cannot be in the future
• Validation messages
  • Messages are user-friendly and can be localized
  • Validation errors surface in a consistent format across APIs

Security and authentication

• JWT workflow
  • User provides credentials to a secure login endpoint.
  • If valid, the server issues a JWT with claims for user identity and roles.
  • Protected endpoints require a valid token in the Authorization header.
  • Token refresh mechanism for long-lived sessions.
• Roles and permissions
  • Admins can create, update, delete employees.
  • Regular users can read and perform limited updates.
  • Security rules are enforced at the method level and via URL patterns.
• Best practices
  • Use short-lived tokens with refresh tokens
  • Store secret keys securely (environment variables or a secrets manager)
  • Enable CSRF protection for browser clients and stateless API clients via appropriate headers

Exception handling

• Uniform error payload
  • code: numeric error code
  • message: human-friendly summary
  • details: optional technical details for debugging
• Global exception handler
  • Catches known exceptions and returns meaningful HTTP status codes
  • Logs stack traces for server-side debugging while returning safe messages to clients
• Common error scenarios
  • Invalid input data (400)
  • Resource not found (404)
  • Unauthorized (401) and forbidden (403)
  • Internal server error (500)

API documentation and developer experience

• Swagger/OpenAPI
  • API docs are automatically generated from code annotations
  • Interactive API explorer for testing endpoints
  • Useful for onboarding and integration work
• Sample requests
  • Quick-start examples for common operations
  • Clear request/response payload shapes
• API versioning
  • Versioned endpoints to ensure forward compatibility

Caching

• Purpose
  • Improve response times for read-heavy endpoints
  • Reduce load on the database during peak traffic
• Implementation
  • Spring Cache abstraction with a simple in-memory provider
  • Cacheable annotations on frequently read endpoints
  • Cache eviction on write operations
• Best practices
  • Tune cache size and eviction policies to match data access patterns
  • Consider using a distributed cache if you scale across multiple instances

Pagination

• User-focused pagination
  • page and size parameters control the result set
  • support for sorting and filtering
• Server-side performance
  • Database-level pagination ensures efficient queries
  • Consistent pagination metadata in responses
• Practical usage
  • /employees?page=0&size=20&sort=lastName,asc
  • Useful when exporting data or building dashboards

File uploads

• Endpoint design
  • Upload endpoints accept multipart/form-data
  • Files assigned to an employee or stored as assets
• Storage options
  • Local file system for development
  • Cloud storage or blob stores for production
• Validation
  • Enforce file size and type restrictions
  • Scan for malware or inappropriate content when appropriate

Spring Actuator

• Observability
  • Health checks confirm application readiness
  • Metrics provide visibility into performance
  • Environment and config data expose runtime state
• Security considerations
  • Protect Actuator endpoints in production
  • Use a dedicated security policy and, if needed, IP whitelisting

Microservices integration

• Clear module boundaries
  • Independent services for employee data, authentication, and notifications
  • Loose coupling via REST APIs or messaging
• Service discovery and resilience
  • Optional integration with service discovery tools
  • Circuit breakers, retries, and timeouts for reliability
• API contracts
  • Stable interfaces with well-defined payloads
  • Versioning to prevent breaking changes
• Deployment patterns
  • Containerized services with a shared data model
  • Centralized configuration and logging

Testing strategy

• Unit tests
  • Focused tests for services, validators, and utility classes
  • Mock repositories and external dependencies
• Integration tests
  • End-to-end tests for controllers, services, and data access
  • In-memory databases for fast feedback
• Property-based tests
  • If applicable, validate data generation correctness
• Test coverage
  • Strive for meaningful coverage across critical flows
  • Regularly review and improve test cases

Logging and observability

• Structured logging
  • Log important events with consistent keys
  • Include context like user identifiers where appropriate
• Log levels
  • Use appropriate levels (.info, .debug, .error) as per importance
• Centralized monitoring
  • Integrate with your existing monitoring stack
  • Collect metrics for performance and reliability

Deployment and packaging

• Build artifacts
  • JAR packages for standalone deployment
  • Docker images for containerized environments
• Environment configuration
  • Externalize configuration via environment variables
  • Provide defaults suitable for development and testing
• Continuous integration
  • CI pipelines to run tests and build artifacts on push or pull requests
• Deployment checklist
  • Validate security settings and credentials
  • Verify data source configurations
  • Confirm healthy startup with Actuator checks

Usage and onboarding

• Developer onboarding
  • Quick start steps to spin up the app locally
  • A tour of the codebase and key modules
• API-focused onboarding
  • How to authenticate and obtain a token
  • Overview of primary endpoints and typical requests
• Debugging tips
  • Common startup issues and how to resolve them
  • How to enable verbose logging for troubleshooting

Releases and upgrades

• About releases
  • Release builds bundle the application and assets needed to run it
  • Each release includes a complete package and documentation
• Accessing releases
  • The main releases page hosts all artifacts for download
  • For the latest release, visit the releases page to download the package
  • See the releases page for details, changes, and upgrade notes
• Upgrading
  • Review breaking changes and migration notes before upgrading
  • Update dependencies to compatible versions
  • Test critical paths after upgrading
• Link to releases
  • See the releases page for download: https://github.com/Tedytobias/SpringBoot-Employeee-Management-Project/releases

Contributing

• How to contribute
  • Fork the repository
  • Create a feature or bugfix branch
  • Open a pull request with a clear description
• Coding standards
  • Follow the project’s style guidelines
  • Add tests for new features or fixes
• Issue reporting
  • Use clear, reproducible steps
  • Include logs or error messages when possible

License

• This project is licensed under the terms defined in the LICENSE file.
• See LICENSE for details.

Downloads and practical notes

• The repository is designed to be run locally with a simple setup. The release packaging makes it easy to deploy in a controlled environment. Since the link points to a releases page, you can download the latest release package and execute the main artifact to run the project in your environment. The releases page is the primary source for stable builds, and it provides the exact artifacts you need for deployment. For quick access, visit the Releases page here: https://github.com/Tedytobias/SpringBoot-Employeee-Management-Project/releases

Design decisions and rationale

• Simplicity in development: The in-memory H2 database offers a fast, frictionless start for developers. It’s easy to switch to a persistent store later without large rewrites.
• Real-world patterns: JWT security, Swagger documentation, and robust exception handling reflect common enterprise needs.
• Extensibility: The architecture is modular. You can add more entities, services, or microservices without major changes to existing code.
• Observability first: Actuator endpoints and structured logging help you monitor health, performance, and potential issues early in the lifecycle.
• Performance considerations: Caching and pagination address common performance bottlenecks in data-heavy apps.

Architecture diagrams and visuals

• The project includes a clean separation between controllers, services, and data access layers.
• A simple diagram can illustrate how a request flows from the REST controller to the service layer, through the repository, and back as a response.
• For larger systems, you can extend the diagram to show microservices boundaries, message queues, or event-driven components.

Code quality and maintainability

• Clean code practices
  • Clear naming and responsibilities
  • Small, testable units
  • Use of DTOs to separate API contracts from internal models
• Documentation
  • Inline comments for complex logic
  • API docs via Swagger to reduce external documentation overhead
• Testing culture
  • A strong focus on unit and integration tests
  • Regular test runs to prevent regressions

Customization ideas

• Swap the database: Replace H2 with PostgreSQL or MySQL. Update the datasource configuration, and run migration scripts if needed.
• Add more entities: Extend the domain with departments, roles, or payroll data.
• Enhance security: Implement refresh tokens, role-based access control, and stronger password hashing strategies.
• Internationalization: Provide messages in multiple languages for broader adoption.
• Observability: Integrate distributed tracing with a tool like OpenTelemetry.

Troubleshooting quick tips

• If the app fails to start, check the logs for configuration issues, port conflicts, or missing environment variables.
• If JWT validation fails, verify the secret key and token expiration settings.
• If endpoints return 4xx where you expect 2xx, verify request payloads against the OpenAPI spec and ensure all required fields pass validation.
• If caching isn’t effective, review cache configuration and verify that write operations invalidate cache entries correctly.

Notes on security and privacy

• Do not hard-code sensitive information in source code or configuration files. Use environment variables or a secrets manager for credentials and tokens.
• When deploying, enable appropriate security measures for production, including TLS, secure cookies, and proper token lifetimes.

Environment and platform compatibility

• Java: Ensure compatibility with your chosen Spring Boot version.
• Docker: If you deploy with containers, ensure the base images map ports and volumes consistently.
• Web UI clients: The API is designed for programmatic access. If you plan to expose a user interface, consider secure authentication flows and input validation to prevent vulnerabilities.

Final remarks

• This repository is a practical, hands-on example of building a modern Spring Boot application with essential enterprise features.
• It demonstrates how to structure a project for scalability, security, and maintainability while keeping the code approachable for learners and practitioners alike.

Releases and upgrade notes (expanded)

• The releases page hosts stable builds for various environments. It is the recommended source to obtain tested artifacts. When upgrading, review the release notes for breaking changes, new features, and migration guidance. Run the project locally to verify behavior, and ensure that data migrations, if any, are applied correctly.

Downloads and releases reference

• For direct access to the releases, use the link provided at the beginning of this document and again later in the Downloads and releases reference. The page hosts release artifacts for download and detailed notes about each version. Access it here: https://github.com/Tedytobias/SpringBoot-Employeee-Management-Project/releases

This README provides a detailed map for developers to understand, run, extend, and maintain the project. It is designed to be practical, precise, and useful for both new contributors and seasoned engineers.