tl;dr Enable code completion of Java types in your TypeScript project.
Annotations: 
This project emits TypeScript types from Java sources.
jtsgen is implemented as an annotation processor, therefore it should be
easily integrated in your current build infrastructure. So here are the
prominent features:
- Emitting types and documentation from annotated Java classes and interfaces at compile time
- Several module types and output variants supported
- read only and name space support
- configured at source the code location (package annotation)
The documentation, including an introduction and a complete list of all features, is available on:
--> http://jtsgen.readthedocs.io <--
So here is a small demo:
As you can see, if the IDE is configured correctly, the java sources are converted immediately.
No Warranty. As stated in the GPL v3 licence, there is no warranty of any kind by using this software.
The following licenses apply jtsgen:
The annotations are Apache 2.0 licensed. The other parts of jtsgen,
especially the processor, are GPLv3 licensed. The license texts are
included in the file LICENSE. Because jtsgen as a sort of a compiler
plugin you shouldn't redistribute the compiler in your projects. It's
just like using OpenJDK: the generated code is not affected by
it's license, so it should be safe using it in most cases. Everything in
this chapter is not a legal advice in any form.
This project has to include the following legal notes:
- Oracle and Java are registered trademarks of Oracle and/or its affiliates. Other names may be trademarks of their respective owners. See https://www.oracle.com/legal/trademarks.html for details.