Java Users REST API

A scalable RESTful Web API built with Java and Spring Boot, using Spring Data JPA for persistence and MySQL as the relational database.

This project demonstrates core engineering practices layered architecture, REST conventions, validation, and clean persistence boundaries applied in the Java/Spring ecosystem.

Features

• RESTful CRUD operations for users
• Persistence with Spring Data JPA (Hibernate)
• MySQL relational database
• Automatic CreatedAt timestamp on user creation
• Role-based user model (Role field)

Tech stack

Layer	Technology
Language	Java 17+
Framework	Spring Boot 3.x
Persistence	Spring Data JPA
Database	MySQL 8+
Build	Maven (or Gradle)

Data model

Table: users

Column	Type	Notes
id	INT, PK, AI	Auto-increment primary key
name	VARCHAR	User display name
email	VARCHAR	Unique email
password	VARCHAR	Stored hashed (never plain text)
role	VARCHAR	e.g. USER, ADMIN
created_at	TIMESTAMP	Set at creation time

Prerequisites

• JDK 17+
• Maven or Gradle
• MySQL Server (running locally or via Docker)
• (Optional) MySQL client or GUI (DBeaver, Workbench) for SQL/debugging

Getting started

1. Clone the repository

git clone https://github.com/lj-soares-eng/java-api.git
cd java-api

2. Create the database

CREATE DATABASE users_api;
USE users_api;
CREATE TABLE users (
    id INT AUTO_INCREMENT PRIMARY KEY,
    name VARCHAR(255) NOT NULL,
    email VARCHAR(255) NOT NULL UNIQUE,
    password VARCHAR(255) NOT NULL,
    role VARCHAR(50) NOT NULL,
    created_at TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP
);

3. Configure the application

Update src/main/resources/application.properties (or application.yml):

spring.datasource.url=jdbc:mysql://localhost:3306/users_api
spring.datasource.username=your_user
spring.datasource.password=your_password
spring.jpa.hibernate.ddl-auto=validate
spring.jpa.show-sql=true
spring.jpa.properties.hibernate.dialect=org.hibernate.dialect.MySQLDialect

Use ddl-auto=update only during early development if you prefer Hibernate to manage schema changes.

4. Run the API

./mvnw spring-boot:run

Or with Gradle:

./gradlew bootRun

The API runs at http://localhost:8080 by default.

API endpoints

Method	Endpoint	Description
GET	/api/users	List all users
GET	/api/users/{id}	Get user by ID
POST	/api/users	Create a user
PUT	/api/users/{id}	Update a user
DELETE	/api/users/{id}	Delete a user

Example: create user

curl -X POST http://localhost:8080/api/users \
  -H "Content-Type: application/json" \
  -d '{
    "name": "Jane Doe",
    "email": "jane@example.com",
    "password": "your-secure-password",
    "role": "USER"
  }'

Passwords must be hashed server-side (e.g. BCrypt). Do not return password in API responses.

Project structure

src/main/java/com/example/api/
├── ApiApplication.java
├── controller/     # REST controllers
├── model/          # JPA entities
├── repository/     # Spring Data repositories
├── service/        # Business logic
└── dto/            # Request/response objects (optional)

Security notes

• Hash passwords before persisting (BCryptPasswordEncoder or similar).
• Exclude password from JSON responses.
• Validate input (@Valid, Bean Validation).
• Use HTTPS in production.

License

MIT (or specify your license here.)

Author

Lucas Soares — GitHub