How to open Javadoc JAR file in web browser
- Rename the file vertx-http-server-branch-4.14.7.1_d4-javadoc.jar to vertx-http-server-branch-4.14.7.1_d4-javadoc.zip
- Use your favourite unzip tool (WinRAR / WinZIP) to extract it, now you have a folder vertx-http-server-branch-4.14.7.1_d4-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 "vertx-http-server-branch-4.14.7.1_d4-sources.jar" -d "vertx-http-server-branch-4.14.7.1_d4-javadoc" -subpackages 
