code: public void init(FilterConfig filterConfig) throws ServletException {
  		// need the Context for Logging, instantiating ClassLoader, etc
  		context = filterConfig.getServletContext();
  		StringBuilder sb = new StringBuilder();
  		StringBuilder err = new StringBuilder(); 
  		Object attr = context.getAttribute(Config.PATHFILTER_NS);
  		if(attr==null) {
  			err.append("PathFilter - pathfilter_ns is not set");
  		} else {
  			sb.append(attr.toString()); 
  		}
  
  		attr = context.getAttribute(Config.PATHFILTER_STACK);
  		if(attr==null) {
  			log.info("PathFilter - No pathfilter_stack set, ignoring");
  		} else {
  			sb.append('.');
  			sb.append(attr.toString());
  		}
  
  		attr = context.getAttribute(Config.PATHFILTER_URLPATTERN);
  		if(attr==null) {
  			log.info("PathFilter - No pathfilter_urlpattern set, defaulting to 'urlpattern'");
  			sb.append(".urlpattern");
  		} else {
  			sb.append('.');
  			sb.append(attr.toString());
  		}
  
  		log.info("PathFilter - AAF Permission Type is",sb.toString());
  		
  		sb.append('|');
  		
  		aaf_type = sb.toString();
  
  		attr = context.getAttribute(Config.PATHFILTER_NOT_AUTHORIZED_MSG);
  		if(attr==null) {
  			not_authorized_msg = "Forbidden - Not Authorized to access this Path";
  		} else {
  			not_authorized_msg = attr.toString();
  		}
  
  		if(err.length()>0) {
  			throw new ServletException(err.toString());
  		}
  	}
docs: Init
  
  Standard Filter "init" call with FilterConfig to obtain properties.  POJOs can construct a
  FilterConfig with the mechanism of their choice, and standard J2EE Servlet engines utilize this
  mechanism already.