How to resolve "javadoc: warning - Multiple sources of package comments found for package a.b.c"?

Question

I am very much outdated, but I have just upgraded my project to use JDK 1.5 from JDK 1.4, and now when running mvn javadoc:javadoc, I encounter the following javadoc warnings:

[WARNING] javadoc: warning - Multiple sources of package comments found for package "com.a"
[WARNING] javadoc: warning - Multiple sources of package comments found for package "com.b"
[WARNING] javadoc: warning - Multiple sources of package comments found for package "com.c"
[WARNING] javadoc: warning - Multiple sources of package comments found for package "com.a"

What do I need to do to fix them? Has anything changed from JDK 1.4 to 1.5?

Thanks!

Answer 1

(Updated 10 years after the original answer.)

An old thread in the Oracle forums discussed this. (Unfortunately the link is broken now, and I can't find the same thread in the new Oracle Developer community, nor in the Wayback machine).

As far as I recall (and could gather from a bit of google-ing), the behavior of javadoc changed between JDK 1.4 and 1.5 so that a package documentation encountered multiple times creates this warning. This seems to have happened specifically with older versions of Maven – updating to a newer version of Maven (or the maven-javadoc-plugin) seems to have helped.

(Of course, that meant a Maven version which was current in 2011, so any version you might have nowadays should be fine.)