1. Download the source tarball with uscan.

2. Package only the source files in lib/java/src.

3. Update debian/pom.xml by downloading the file from e.g. https://mvnrepository.com/artifact/org.apache.thrift/libthrift/0.13.0

4. Check the official jar file if the MANIFEST has changed and copy the contents to debian/libthrift-java.manifest if necessary.

5. Thus we can avoid Gradle (yeah)
