🚀 Issue Tracker API — Spring Boot Backend Project

A fully tested RESTful backend application demonstrating clean architecture, exception handling, and professional Spring Boot testing practices.

This project reflects how a modern Java backend service is structured, tested, and maintained in a professional environment.

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🔍 Why This Project Matters

This API was built to showcase:

• Clean RESTful API design
• Separation of concerns across Controller / Service / Repository
• Defensive programming with centralized exception handling
• Confidence in code through full test coverage
• Hands-on experience with Spring Boot + JPA

It mirrors patterns commonly used in production backend systems.

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🧰 Tech Stack

• Java 25
• Spring Boot 3.5.9
• Spring Web
• Spring Data JPA
• H2 In-Memory Database
• JUnit 5
• Mockito
• MockMvc
• Maven

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🏗 Architecture Overview

Controller → Service → Repository → Database

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Each layer is:

• Independently testable
• Clearly scoped
• Designed to prevent tight coupling

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📁 Project Structure

src ├── main │ ├── java │ │ └── com.ambrogio.issuetracker │ │ ├── controller // REST endpoints │ │ ├── service // Business logic │ │ ├── repository // Data access (JPA) │ │ ├── model // Domain entities │ │ ├── exception // Custom + global errors │ │ └── IssuetrackerApplication.java │ └── resources │ └── application.properties │ ├── test │ └── java │ └── com.ambrogio.issuetracker │ ├── controller // @WebMvcTest │ ├── service // Mockito unit tests │ └── repository // @DataJpaTest

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🌐 API Endpoints

Method	Endpoint	Description
GET	/issues	Retrieve all issues
GET	/issues/{id}	Retrieve issue by ID
POST	/issues	Create a new issue
DELETE	/issues/{id}	Delete issue by ID

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⚠️ Centralized Error Handling

All errors are handled consistently using @ControllerAdvice.

This ensures predictable responses for clients and clean controller code.

🧪 Testing Strategy (Key Highlight) This project includes three layers of automated testing, mirroring industry best practices.

✅ Controller Tests (@WebMvcTest) Tests HTTP request/response behavior

Uses MockMvc

Service layer fully mocked

Verifies status codes and JSON payloads

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✅ Service Tests (Mockito) Pure business logic testing

Repository mocked

Covers success and failure scenarios

Ensures correctness independent of database

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✅ Repository Tests (@DataJpaTest) Uses real JPA + H2 database

Validates persistence behavior

Tests save, find, delete operations

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🧪 API Validation with Postman DELETE — Success (204 No Content) 📸

DELETE — Missing Resource (404 Not Found) 📸

▶️ Running the Application Locally bash Copy code git clone https://github.com/YOUR_USERNAME/issuetracker.git cd issuetracker ./mvnw spring-boot:run Application:

arduino Copy code http://localhost:8080 H2 Console:

bash Copy code http://localhost:8080/h2-console 📌 Key Engineering Takeaways REST APIs designed with correct HTTP semantics

Clean service-oriented architecture

Robust exception handling strategy

High confidence through test isolation

Real database testing (not mocked persistence)

🚧 Potential Enhancements Swagger / OpenAPI documentation

Pagination & sorting

Authentication & authorization

Dockerized deployment

CI pipeline with GitHub Actions

👤 Author Ambrogio Bailey Aspiring Software Engineer focused on Java backend development, Spring Boot, and building production-ready systems with strong testing practices.

GitHub: https://github.com/AmbrogioBailey LinkedIn: https://www.linkedin.com/in/ambrogio-bailey-b67529373/