How to open Javadoc JAR file in web browser
- Rename the file scalac-scapegoat-plugin_2.12.12-1.4.8-javadoc.jar to scalac-scapegoat-plugin_2.12.12-1.4.8-javadoc.zip
- Use your favourite unzip tool (WinRAR / WinZIP) to extract it, now you have a folder scalac-scapegoat-plugin_2.12.12-1.4.8-javadoc
- Double click index.html will open the index page on your default web browser.
How to generate Javadoc from a source JAR?
Running the command javadoc:
javadoc --ignore-source-errors -encoding UTF-8 -sourcepath "scalac-scapegoat-plugin_2.12.12-1.4.8-sources.jar" -d "scalac-scapegoat-plugin_2.12.12-1.4.8-javadoc" -subpackages 
