jpackage should create copyright file in /usr/share/doc directory tree when building .deb package for Java runtime with installation directory in /usr directory tree.

jpackage creates share/doc/copyright file in installation directory for apps installed outside of /usr tree.

jpackage creates /usr/share/doc/${package_name}/copyright file for apps installed in /usr tree .

jpackage doesn't create copyright file at all for Java runtime. The reason for this behavior was that jpackage should not place additional files in installation directory of Java runtime. However when installing Java runtime or app in /usr tree, copyright file will be placed outside of installation directory. Thus copyright file should be always created if package installation directory is inside of /usr tree.