You should try Angular2Boot http://lteconsulting.fr/angular2boot/ which allows you to write your Angular 2 application in full Java 8 language.
Especially the bootstrapping phase is much more convenient (one dependency in you maven or gradle build file). There is also a maven archetype which gets you going with a working application in one minute.
More is that since the Angular2Boot uses Java annotations with the same names as the typescript decorators, you can just read the typescript documentation and guess easily what to use for Java.
Another point is that when breaking changes are made in the Angular 2 API, since your code is in Java, refactoring is a lot easier than with TS or JS!