Spring Boot

Overview

Spring Boot is a Java framework that makes it easy to create stand-alone, production-grade applications. It provides auto-configuration, embedded servers, and an opinionated approach to building REST APIs and web applications.

Quick Start

git clone https://<git-server>/<username>/<repo-name>.git
cd <repo-name>

spring.datasource.url=jdbc:mysql://db.<session-domain>:3306/<username>
spring.datasource.username=<username>
spring.datasource.password=<password>

./mvnw spring-boot:run

git add .
git commit -m "Initial setup"
git push origin main

Local Development with Docker

If you don't have Java installed locally, you can use Docker to build and run your Spring Boot application.

Running Commands with Docker

# Build the project
docker run --rm -v $(pwd):/app -w /app maven:3-eclipse-temurin-21 ./mvnw clean package -DskipTests

# Run the application
docker run --rm -v $(pwd):/app -w /app -p 8080:8080 eclipse-temurin:21 java -jar target/*.jar

Database Configuration

The NStrim platform provides you with a MySQL/MariaDB database. Configure your application.properties file with the correct credentials.

Full Configuration

spring.datasource.url=jdbc:mysql://db.<session-domain>:3306/<username>
spring.datasource.username=<username>
spring.datasource.password=<password>
spring.datasource.driver-class-name=com.mysql.cj.jdbc.Driver

spring.jpa.hibernate.ddl-auto=update
spring.jpa.show-sql=true

Project Structure

├── src/
│   └── main/
│       ├── java/com/example/
│       │   ├── Application.java          # Spring Boot entry point
│       │   ├── controllers/              # REST controllers
│       │   ├── models/                   # JPA entities
│       │   ├── repositories/             # Spring Data repositories
│       │   └── services/                 # Business logic
│       └── resources/
│           ├── application.properties    # Configuration
│           ├── templates/                # Thymeleaf templates
│           └── static/                   # CSS, JS, images
├── pom.xml                               # Maven dependencies
└── Dockerfile                            # Docker config
        

Common Tasks

Creating a REST Controller

@RestController
@RequestMapping("/api/users")
public class UserController {

    @GetMapping
    public List<User> getAll() {
        return userRepository.findAll();
    }

    @PostMapping
    public User create(@RequestBody User user) {
        return userRepository.save(user);
    }
}

Creating a JPA Entity

@Entity
@Table(name = "users")
public class User {
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Long id;

    private String name;
    private String email;

    // getters and setters
}

Creating a Repository

public interface UserRepository extends JpaRepository<User, Long> {
    Optional<User> findByEmail(String email);
}

Useful Commands

Troubleshooting

Deployment Workflow