A simple DropWizard extension for integrating Guice via a bundle. It optionally uses classpath scanning courtesy of the Reflections project to discover resources and more to install into the dropwizard environment upon service start.
<dependencies>
<dependency>
<groupId>com.hubspot.dropwizard</groupId>
<artifactId>dropwizard-guice</artifactId>
<version>0.7.0.2</version>
</dependency>
</dependencies>Simply install a new instance of the bundle during your service initialization
public class HelloWorldApplication extends Application<HelloWorldConfiguration> {
private GuiceBundle<HelloWorldConfiguration> guiceBundle;
public static void main(String[] args) throws Exception {
new HelloWorldApplication().run(args);
}
@Override
public void initialize(Bootstrap<HelloWorldConfiguration> bootstrap) {
guiceBundle = GuiceBundle.<HelloWorldConfiguration>newBuilder()
.addModule(new HelloWorldModule())
.setConfigClass(HelloWorldConfiguration.class)
.build();
bootstrap.addBundle(guiceBundle);
}
@Override
public String getName() {
return "hello-world";
}
@Override
public void run(HelloWorldConfiguration helloWorldConfiguration, Environment environment) throws Exception {
environment.jersey().register(HelloWorldResource.class);
environment.lifecycle().manage(guiceBundle.getInjector().getInstance(TemplateHealthCheck.class));
}
}Lastly, you can enable auto configuration via package scanning.
public class HelloWorldApplication extends Application<HelloWorldConfiguration> {
public static void main(String[] args) throws Exception {
new HelloWorldApplication().run(args);
}
@Override
public void initialize(Bootstrap<HelloWorldConfiguration> bootstrap) {
GuiceBundle<HelloWorldConfiguration> guiceBundle = GuiceBundle.<HelloWorldConfiguration>newBuilder()
.addModule(new HelloWorldModule())
.enableAutoConfig(getClass().getPackage().getName())
.setConfigClass(HelloWorldConfiguration.class)
.build();
bootstrap.addBundle(guiceBundle);
}
@Override
public String getName() {
return "hello-world";
}
@Override
public void run(HelloWorldConfiguration helloWorldConfiguration, Environment environment) throws Exception {
// now you don't need to add resources, tasks, healthchecks or providers
// you must have your health checks inherit from InjectableHealthCheck in order for them to be injected
}
}If you are having trouble accessing your Configuration or Environment inside a Guice Module, you could try using a provider.
public class HelloWorldModule extends AbstractModule {
@Override
protected void configure() {
// anything you'd like to configure
}
@Provides
public SomePool providesSomethingThatNeedsConfiguration(HelloWorldConfiguration configuration) {
return new SomePool(configuration.getPoolName());
}
@Provides
public SomeManager providesSomenthingThatNeedsEnvironment(Environment env) {
return new SomeManager(env.getSomethingFromHere()));
}
}You can also replace the default Guice Injector by implementing your own InjectorFactory. For example if you want
to use Governator you can create the following implementation:
public class GovernatorInjectorFactory implements InjectorFactory {
@Override
public Injector create( final Stage stage, final List<Module> modules ) {
return LifecycleInjector.builder().inStage( stage ).withModules( modules ).build()
.createInjector();
}
}and then set the InjectorFactory when initializing the GuiceBundle:
@Override
public void initialize(Bootstrap<HelloWorldConfiguration> bootstrap) {
GuiceBundle<HelloWorldConfiguration> guiceBundle = GuiceBundle.<HelloWorldConfiguration>newBuilder()
.addModule(new HelloWorldModule())
.enableAutoConfig(getClass().getPackage().getName())
.setConfigClass(HelloWorldConfiguration.class)
.setInjectorFactory( new GovernatorInjectorFactory() )
.build();
bootstrap.addBundle(guiceBundle);
}Please fork an example project if you'd like to get going right away.
Enjoy!