JAutodoc is an Eclipse Plugin for automatic adding Javadoc and file headers to your source code. It optionally generates initial comments from element name. Starting with Release 1.3 of JAutodoc it is possible to define Velocity templates for Javadoc and file headers.
What I usually do is, in Eclipse preferences, I define an Installed JRE called "JDK X.Y.Z" and include tools.jar as part of it libraries. Then I change the project preferences to use that JRE "JDK X.Y.Z".