Getting Started with JBang

Get Started with JBang in 5 Minutes

JBang makes Java development effortless. Whether you're a seasoned developer or just starting with Java, JBang eliminates the complexity of traditional Java development.

🚀 Quick Installation

Choose your platform and install JBang in seconds:

macOS & Linux:

curl -Ls https://sh.jbang.dev | bash -s - app setup

Windows (PowerShell):

iex "& { $(iwr https://ps.jbang.dev) } app setup"

Docker:

docker run -it jbangdev/jbang

📝 Your First JBang Script

Create a file called hello.java:

public class hello {
    public static void main(String[] args) {
        System.out.println("Hello, JBang!");
        System.out.println("Java version: " + System.getProperty("java.version"));
    }
}

Run it instantly:

jbang hello.java

That's it! No compilation, no classpath setup, no build files.

🔧 Adding Dependencies

JBang automatically downloads and manages dependencies. Add them directly in your source code:

//DEPS org.springframework.boot:spring-boot-starter-web:3.2.0
//DEPS org.springframework.boot:spring-boot-starter-data-jpa:3.2.0

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;

@SpringBootApplication
@RestController
public class app {
    
    @GetMapping("/")
    public String hello() {
        return "Hello from Spring Boot + JBang!";
    }
    
    public static void main(String[] args) {
        SpringApplication.run(app.class, args);
    }
}

Run with:

jbang app.java

🎯 Common Use Cases

For Junior Developers

Learning Java Fundamentals:

//DEPS org.junit.jupiter:junit-jupiter:5.9.2

import org.junit.jupiter.api.Test;
import static org.junit.jupiter.api.Assertions.*;

public class CalculatorTest {
    
    @Test
    public void testAddition() {
        assertEquals(4, 2 + 2);
    }
    
    public static void main(String[] args) {
        // Run tests
        org.junit.platform.launcher.LauncherFactory
            .create()
            .execute(org.junit.platform.launcher.core.LauncherDiscoveryRequestBuilder
                .request()
                .selectors(org.junit.platform.engine.discovery.DiscoverySelectors
                    .selectClass(CalculatorTest.class))
                .build());
    }
}

For Senior Developers

Quick Prototyping:

//DEPS io.quarkus:quarkus-resteasy-reactive:3.2.0.Final
//DEPS io.quarkus:quarkus-hibernate-orm-panache:3.2.0.Final
//DEPS io.quarkus:quarkus-jdbc-postgresql:3.2.0.Final

import io.quarkus.runtime.Quarkus;
import io.quarkus.runtime.annotations.QuarkusMain;

@QuarkusMain
public class QuickAPI {
    public static void main(String[] args) {
        Quarkus.run(args);
    }
}

DevOps Scripts:

//DEPS com.fasterxml.jackson.core:jackson-databind:2.15.2
//DEPS org.apache.httpcomponents.client5:httpclient5:5.2.1

import com.fasterxml.jackson.databind.ObjectMapper;
import org.apache.hc.client5.http.classic.methods.HttpGet;
import org.apache.hc.client5.http.impl.classic.CloseableHttpClient;
import org.apache.hc.client5.http.impl.classic.HttpClients;

public class HealthCheck {
    public static void main(String[] args) throws Exception {
        try (CloseableHttpClient client = HttpClients.createDefault()) {
            HttpGet request = new HttpGet("https://api.github.com/status");
            String response = client.execute(request, 
                response1 -> new String(response1.getEntity().getContent().readAllBytes()));
            
            ObjectMapper mapper = new ObjectMapper();
            var status = mapper.readTree(response);
            System.out.println("GitHub Status: " + status.get("status").get("description"));
        }
    }
}

🌟 Advanced Features

Run from URLs

jbang https://github.com/jbangdev/jbang-catalog/blob/main/jbang/Hello.java

Use Different Java Versions

//JAVA 17
//DEPS org.springframework.boot:spring-boot-starter-web:3.2.0

public class app {
    public static void main(String[] args) {
        System.out.println("Running on Java " + System.getProperty("java.version"));
    }
}

IDE Integration

JBang works seamlessly with:

• IntelliJ IDEA: Full support with syntax highlighting and debugging
• VS Code: Java extension pack works out of the box
• Eclipse: Java development tools recognize JBang files
• Vim/Emacs: Syntax highlighting and code completion

📚 Next Steps

1. Explore the AppStore: Visit jbang.dev/appstore to discover applications
2. Join the Community: Follow us on GitHub and Twitter
3. Read the Documentation: Check out our comprehensive docs
4. Share Your Code: Create catalogs and share your JBang applications

🆘 Need Help?

• Documentation: jbang.dev/documentation
• GitHub Issues: github.com/jbangdev/jbang/issues
• Community: GitHub Discussions

Ready to unleash the power of Java? Start building with JBang today!