REST API with Spring Boot and Java

A RESTful web service built with Spring Boot 3.4.0, Java 21, and MySQL, featuring person management with API versioning, custom mappers, and comprehensive exception handling.

🚀 Features

• RESTful API: Full CRUD operations for person management
• API Versioning: Multiple API versions (v1 and v2) for backward compatibility
• Object Mapping: DozerMapper integration and custom mappers for DTO conversion
• Database Integration: MySQL database with JPA/Hibernate
• Exception Handling: Custom exception responses and resource not found handling
• Testing: Unit tests with mocks and comprehensive test coverage
• Logging: Configurable logging levels for debugging and monitoring

🛠️ Technologies Used

• Java 21
• Spring Boot 3.4.0
• Spring Data JPA
• MySQL
• DozerMapper 7.0.0
• Maven
• JUnit 5 (for testing)

📁 Project Structure

src/
├── main/
│   ├── java/br/com/campos/
│   │   ├── controller/          # REST controllers
│   │   │   ├── PersonController.java
│   │   │   └── TestLogController.java
│   │   ├── data/dto/            # Data Transfer Objects
│   │   │   ├── v1/PersonDTO.java
│   │   │   └── v2/PersonDTOV2.java
│   │   ├── exception/           # Exception handling
│   │   │   ├── ExceptionResponse.java
│   │   │   ├── ResourceNotFoundException.java
│   │   │   └── handler/CustomEntityResponseHandler.java
│   │   ├── mapper/              # Object mapping utilities
│   │   │   ├── ObjectMapper.java
│   │   │   └── custom/PersonMapper.java
│   │   ├── model/               # JPA entities
│   │   │   └── Person.java
│   │   ├── repository/          # Data access layer
│   │   │   └── PersonRepository.java
│   │   ├── services/            # Business logic layer
│   │   │   └── PersonServices.java
│   │   ├── converters/          # Utility converters
│   │   │   └── NumberConverter.java
│   │   └── Startup.java         # Main application class
│   └── resources/
│       └── application.yml      # Application configuration
└── test/
    └── java/br/com/campos/
        ├── unitTests/mapper/    # Unit tests for mappers
        └── StartupTests.java    # Integration tests

🚀 Getting Started

Prerequisites

• Java 21 or higher
• Maven 3.6+
• MySQL 8.0+

Environment Variables

Set the following environment variables before running the application:

DATABASE_URL=jdbc:mysql://localhost:3306/your_database
DATABASE_USERNAME=your_username
DATABASE_PASSWORD=your_password

Installation

1. Clone the repository

   git clone <repository-url>
   cd spring-boot-and-java

2. Build the project

   mvn clean install

3. Run the application

   mvn spring-boot:run

The application will start on http://localhost:8080

📚 API Documentation

Person Management API

Base URL: /person

Method	Endpoint	Description	Request Body	Response
GET	/person/{id}	Get person by ID	-	PersonDTO
GET	/person	Get all persons	-	List<PersonDTO>
POST	/person	Create new person (v1)	PersonDTO	PersonDTO
POST	/person/v2	Create new person (v2)	PersonDTOV2	PersonDTOV2
PUT	/person	Update existing person	PersonDTO	PersonDTO
DELETE	/person/{id}	Delete person by ID	-	204 No Content

API Versioning

The API supports multiple versions:

• v1: Standard PersonDTO with basic fields
• v2: Enhanced PersonDTOV2 with additional fields and features

Request/Response Examples

Create Person (v1)

POST /person
Content-Type: application/json

{
  "firstName": "John",
  "lastName": "Doe",
  "address": "123 Main St",
  "gender": "Male"
}

Create Person (v2)

POST /person/v2
Content-Type: application/json

{
  "firstName": "Jane",
  "lastName": "Smith",
  "address": "456 Oak Ave",
  "gender": "Female"
  // Additional v2-specific fields
}

🗄️ Database Schema

Person Table

CREATE TABLE person (
  id BIGINT AUTO_INCREMENT PRIMARY KEY,
  first_name VARCHAR(80) NOT NULL,
  last_name VARCHAR(80) NOT NULL,
  address VARCHAR(100) NOT NULL,
  gender VARCHAR(6) NOT NULL
);

🔧 Configuration

Application Configuration (application.yml)

spring:
  application:
    name: rest-with-spring-boot-and-java
  datasource:
    driver-class-name: com.mysql.cj.jdbc.Driver
    url: ${DATABASE_URL}
    username: ${DATABASE_USERNAME}
    password: ${DATABASE_PASSWORD}
  jpa:
    hibernate:
      ddl-auto: update
    show-sql: false
    open-in-view: false

logging:
  level:
    br.com.campos: DEBUG

🧪 Testing

Running Tests

# Run all tests
mvn test

# Run specific test class
mvn test -Dtest=ObjectMapperTests

Test Structure

• Unit Tests: Located in src/test/java/br/com/campos/unitTests/
• Mock Data: Utility classes for generating test data
• Integration Tests: End-to-end testing of the application

📊 Architecture

Layered Architecture

1. Controller Layer: Handles HTTP requests and responses
2. Service Layer: Contains business logic
3. Repository Layer: Data access and persistence
4. Model Layer: JPA entities representing database tables

Design Patterns

• DTO Pattern: Separate data transfer objects for API communication
• Repository Pattern: Abstracted data access layer
• Custom Mapper Pattern: Specialized object mapping for complex transformations
• Exception Handling Pattern: Centralized error handling and response formatting

🔄 Object Mapping

The application uses two mapping approaches:

1. DozerMapper: Generic object mapping utility
2. Custom Mappers: Specialized mappers for complex object transformations (e.g., PersonMapper)

📝 Logging

Configurable logging levels:

• DEBUG: Detailed application flow (br.com.campos package)
• INFO: General application information
• WARN/ERROR: Issues and exceptions

🚧 Development Status

This project is currently in active development. Features being worked on:

• Authentication and Authorization
• API Documentation (Swagger/OpenAPI)
• Pagination and Sorting
• Validation Enhancements
• Caching Implementation
• Performance Monitoring
• Docker Support
• CI/CD Pipeline

🤝 Contributing

This project is still under development. Contributions, suggestions, and feedback are welcome as new features are added.

📄 License

This project is a demo/learning project for Spring Boot development.

📞 Contact

For questions or suggestions about this project, please open an issue in the repository.

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Note: This README will be updated as new features and functionalities are added to the project.