{% extends "../helloWorld.html" %} {% block demoSectionClasses %}demo_hello_world{% endblock %} {% block meta_title %}Demo - Hello World - Better{% endblock %} {% block meta_description %}"Hello World!" demo and tutorial using Spincast - Better version{% endblock %} {% set demoId = "better" %} {% block demoBody %}

2. Better version

In general, you want to create a custom Guice module for your application, so you can bind custom components. This is what we are going to do in this tutorial. We will also create a controller so our Route Handlers are not defined inline but have their own dedicated method.

First, we add the latest version of the org.spincast:spincast-default Maven artifact to our pom.xml (or build.gradle) : 

<dependency>
    <groupId>org.spincast</groupId>
    <artifactId>spincast-default</artifactId>
    <version>{{spincast.spincastCurrrentVersion}}</version>
</dependency>

Let's then create our controller : 

public class AppController {

    public void index(DefaultRequestContext context) {

        JsonObject user = context.json().create();
        user.put("name", "Stromgol");
        user.put("age", 42);

        context.response().sendJson(user);
    }
}

This controller contains one Route Handler : "index". A Route Handler is a method that receives, as a parameter, an object implementing RequestContext. In this simple handler, we create a "user" object as a JsonObject and we send it as "application/json".

Now, let's create a custom Guice module, so we can bind our components : 

public class AppModule extends SpincastGuiceModuleBase {

    @Override
    protected void configure() {
        
        // Binds our controller
        bind(AppController.class).in(Scopes.SINGLETON);
        
        // ... binds all our other application components here
    }
}

Finally, let's bootstrap and start the application! We do that in the standard main(...) method, using the Bootstrapper : 

public class App {

    public static void main(String[] args) {
        Spincast.configure()
                .module(new AppModule())
                .init(args);
    }

    @Inject
    protected void init(Server server, DefaultRouter router, AppController ctrl) {
        router.GET("/").save(ctrl::index);
        server.start();
    }
}

Explanation :

Try it!

Download this application, and run it by yourself :

The application is then accessible at http://localhost:44419

{% endblock %}