code: public void init(FilterConfig config) throws ServletException {
      super.init(config);
  
      String temp = config.getInitParameter("approot");
  
      if (temp == null) {
        throw new ServletException("Missing required init parameter: approot");
      }
  
      pstate = new PresentationState();
      pstate.setAppRoot(temp);
  
      temp = config.getInitParameter("noxslt");
      pstate.setNoXSLTSticky("yes".equals(temp));
    }
docs: /* (non-Javadoc)
  @see javax.servlet.Filter#init(javax.servlet.FilterConfig)