rules_apidoc

First, load rules_apidoc in your WORKSPACE:

git_repository(
    name = "org_pubref_rules_apidoc",
    remote = "https://github.com/pubref/rules_apidoc.git",
    commit = "HEAD",  # replace with latest version
)

Then, use a BUILD file rule to generate documentation for the language of your choice.

Language	Rule	Description
Java	javadoc	Generate javadoc api documentation.