Run ant from Java

Is there a tutorial on how to run Ant from Java?

Part of my answer to this question might help:

See this article and this article:

   File buildFile = new File("build.xml");
   Project p = new Project();
   p.setUserProperty("ant.file", buildFile.getAbsolutePath());
   p.init();
   ProjectHelper helper = ProjectHelper.getProjectHelper();
   p.addReference("ant.projectHelper", helper);
   helper.parse(p, buildFile);
   p.executeTarget(p.getDefaultTarget());