How to open Javadoc JAR file in web browser
- Rename the file rmspe-weka-package-2021.3.12-javadoc.jar to rmspe-weka-package-2021.3.12-javadoc.zip
- Use your favourite unzip tool (WinRAR / WinZIP) to extract it, now you have a folder rmspe-weka-package-2021.3.12-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 "rmspe-weka-package-2021.3.12-sources.jar" -d "rmspe-weka-package-2021.3.12-javadoc" -subpackages 
