guice-global.java

import com.google.inject.AbstractModule;  
import com.google.inject.Guice;  
import com.google.inject.Injector;  
import play.Application;  
import play.GlobalSettings;  
import services.GreetingService;  
import services.RealGreetingService;

public class Global extends GlobalSettings {

    private Injector injector;

    @Override
    public void onStart(Application application) {
        injector = Guice.createInjector(new AbstractModule() {
            @Override
            protected void configure() {
                bind(GreetingService.class).to(RealGreetingService.class);
            }
        });
    }

    @Override
    public <T> T getControllerInstance(Class<T> aClass) throws Exception {
        return injector.getInstance(aClass);
    }
}