How can I generate javadocs using Java?

Question

I'm writing a Java app that will let me compile a Java project based solely on it's file structure so that I can write code and compile without an IDE. The problem that I'm currently having is that I would like to automatically generate the javadoc while I'm compiling, though while Java 6 supplies a JavaCompiler object to work with, I can't find a way to use the javadoc command.

How can I generate the javadoc html for my projects using Java code?

Answer 1

Just in case you weren't aware both Apache Ant and Apache Maven are tools that exist to accomplish a similar goal to what you are writing (compiling without an IDE).

Both of them have built in support for generating javadoc. Ant syntax looks like this:

<!-- publish javadoc -->
<target name="javadoc" description="Creates javadoc for IMP.">
      <delete dir="${web-javadoc}"/>
      <javadoc sourcepath="${source}"
               defaultexcludes="no"
               destdir="${web-javadoc}"
               author="true"
               version="true"
               use="true"
               windowtitle="IMP: Integrated Mechanisms Program"
               overview="${source}/overview.html"
               classpathref="debug.classpath"
               stylesheetfile="${javadoc-theme}/stylesheet.css"
       />

       <copy file="${javadoc-theme}/javadoc.jpg" tofile="${web-javadoc}/javadoc.jpg"/>
</target>

If you really want to generate it on your own you want to use the Doclet API

import com.sun.javadoc.*;

public class ListClass {
    public static boolean start(RootDoc root) {
        ClassDoc[] classes = root.classes();
        for (int i = 0; i < classes.length; ++i) {
            System.out.println(classes[i]);
        }
        return true;
    }
}