code: public void setClassname(final String className) {
      Object proc = null;
      try {
        final Class<?> implClass = ProjectDef.class.getClassLoader().loadClass(className);
        try {
          final Method getInstance = implClass.getMethod("getInstance");
          proc = getInstance.invoke(null);
        } catch (final Exception ex) {
          proc = implClass.newInstance();
        }
      } catch (final Exception ex) {
        throw new BuildException(ex);
      }
      this.projectWriter = (ProjectWriter) proc;
    }
docs: Class name for a user-supplied project writer. Use the "type"
  attribute to specify built-in project writer implementations.
  
  @param className
  full class name