How to open Javadoc JAR file in web browser
- Rename the file scalatra-json_2.12-3.0.0-M5-javax-javadoc.jar to scalatra-json_2.12-3.0.0-M5-javax-javadoc.zip
- Use your favourite unzip tool (WinRAR / WinZIP) to extract it, now you have a folder scalatra-json_2.12-3.0.0-M5-javax-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 "scalatra-json_2.12-3.0.0-M5-javax-sources.jar" -d "scalatra-json_2.12-3.0.0-M5-javax-javadoc" -subpackages 
