🏃‍♂️ Quick Start

Get up and running with Sprout in just a few minutes!

Prerequisites

• Java 21+ (required for virtual threads and modern language features)
• Gradle (for building the project)

1. Clone & Build

$ git clone https://github.com/yyubin/sprout.git
$ cd sprout && ./gradlew build

2. Run the Application

Java 21 Module Requirements

CGLIB proxies require additional module access flags for deep reflection:

$ java \
  --add-opens=java.base/java.lang=ALL-UNNAMED \
  --add-opens=java.base/java.lang.reflect=ALL-UNNAMED \
  --add-opens=java.base/java.io=ALL-UNNAMED \
  --add-opens=java.base/java.util=ALL-UNNAMED \
  -jar build/libs/sprout.jar

tip

Server mode and thread model are configured via application.yml, not command-line arguments.

3. Your First Application

Main Application Class

@ComponentScan("com.example.app")
public class DemoApplication {
    public static void main(String[] args) throws Exception {
        SproutApplication.run(DemoApplication.class);
    }
}

Simple Controller

@Controller
@RequestMapping("/api")
public class HelloController {
    private final GreetingService service;

    public HelloController(GreetingService service) {
        this.service = service;
    }

    @GetMapping("/hello/{id}")
    public MessageDto hello(@PathVariable Long id) {
        return new MessageDto(service.greet(id));
    }

    @PostMapping("/users")
    public ResponseEntity<User> createUser(@RequestBody CreateUserRequest request) {
        User user = service.createUser(request);
        return ResponseEntity.ok(user);
    }
}

Service with AOP

@Service
public class GreetingService {
    public String greet(Long id) {
        return "Hello, User " + id + "!";
    }

    public User createUser(CreateUserRequest request) {
        // Business logic here
        return new User(request.getName(), request.getEmail());
    }
}

AOP Aspect

@Aspect
public class LoggingAspect {
    @Around(pointcut = "com.example.app..*Service.*")
    public Object logExecutionTime(ProceedingJoinPoint pjp) throws Throwable {
        long startTime = System.nanoTime();
        try {
            return pjp.proceed();
        } finally {
            long duration = (System.nanoTime() - startTime) / 1_000;
            System.out.printf("%s took %d µs%n",
                pjp.getSignature().toLongName(), duration);
        }
    }
}

4. Configuration

Create src/main/resources/application.yml:

author: your-name
server:
  execution-mode: hybrid   # nio | hybrid | blocking
  thread-type: virtual     # virtual | platform
  thread-pool-size: 150    # only when thread-type = platform

sprout:
  database:
    url: jdbc:mysql://localhost:3306/myapp
    username: root
    password: your-password

5. Test Your Application

Once running, test your endpoints:

# GET request
curl http://localhost:8080/api/hello/123

# POST request
curl -X POST http://localhost:8080/api/users \
  -H "Content-Type: application/json" \
  -d '{"name": "John Doe", "email": "john@example.com"}'

What's Next?

• 🏗️ Learn the Architecture - Understand how Sprout works

Having Issues?

• Browse Common Issues
• Join the Community Discussions