Download iDoclet.tar.gz
Check out iContract Extras

iDoclet is an extension of Sun's standard doclet from JDK 1.2 that includes assertion information in the generated API docs.
iDoclet is packaged as a jar file, and can be invoked from Ant in the following way:

<!-- =================================================================== -->
<!-- Creates the API documentation with iDoclet                          -->
<!-- =================================================================== -->
<target name="javadocs" depends="prepare-src" description="Generates the API documentation">
   <mkdir dir="${build.javadocs}"/>
      <doclet name="iContract.doclet.Standard" path="${lib.dir}/iDoclet.jar">
         <param name="-author"/>
         <param name="-use"/>
      <classpath refid="classpath"/>

Note: Some of the options must be specified in the javadoc tag, some in the nested param tags under doclet. I'm not sure why, but it shouldn't be a big problem.

iDoclet is currently being upgraded to be an extension of Sun's standard doclet from JDK 1.3. However, the current version can be used without any problems to document Java code written for JDK 1.3.