jooby: guice module

1. Guice

1) Add Guice dependency to your project:

Maven

Gradle

<dependency>
  <groupId>io.jooby</groupId>
  <artifactId>jooby-guice</artifactId>
  <version>3.0.10</version>
</dependency>

implementation 'io.jooby:jooby-guice:3.0.10'

2) Install Guice:

Installing Guice

Java

Kotlin

import io.jooby.guice.GuiceModule;
import io.jooby.kt.runApp;

public class App extends Jooby {

  {
    install(new GuiceModule());                     (1)

    get("/", ctx -> {
      MyService service = require(MyService.class); (2)
      return service.doSomething();
    });
}

  public static void main(String[] args) {
    runApp(args, App::new);
  }
}

import io.jooby.di.GuiceModule
import io.jooby.kt.runApp

fun main(args: Array<String>) {
  runApp(args) {
    install(GuiceModule())                    (1)

    get ("/") {
      val service = require(MyService::class) (2)
      service.doSomething()
    }
  }
}

1	Install Guice module
2	The require(Class) call is now resolved by Guice

1.1. Property Injection

Configuration properties can be injected using the @Named annotation:

application.conf

currency = USD

Java

Kotlin

import javax.injext.Named;
import javax.injext.Inject;

public class BillingService {

  @Inject
  public BillingService(@Named("currency") String currency) {
    ...
  }

}

class BillingService @Inject constructor(@Named("currency") currency: String) {
  ...
}

1.2. MVC routes

Guice will also provisioning MVC routes

MVC and Guice

Java

Kotlin

import io.jooby.guice.GuiceModule;
import io.jooby.kt.runApp

public class App extends Jooby {

  {
    install(new GuiceModule());  (1)

    mvc(MyController.class);     (2)
  }

  public static void main(String[] args) {
    runApp(args, App::new);
  }
}

import io.jooby.di.GuiceModule
import io.jooby.kt.runApp

fun main(args: Array<String>) {
  runApp(args) {
    install(GuiceModule())       (1)

    mvc(MyController::class)     (2)
  }
}

1	Install Guice module
2	Register a MVC route

The lifecycle of MyController is now managed by Guice. Also:

In Guice, the default scope is prototype (creates a new instance per request)
If you prefer a single instance add the jakarta.inject.Singleton annotation