Play.java

public class Application extends Controller {
 
    @Inject static MyBean myBean;

    public static void index() {
        myBean.currentUserId = session.get("id");
        DataFromSomewhere data = myBean.getData();
        render(data);
    }
}

@RequestScoped
public class MyBean {
    @Inject @FromWS DataClient;
    public String currentUserId;
    public DataFromSomewhere getData() { ... }
}