code: public void visit(final WebAppServlet webAppServlet) {
  		NullArgumentException.validateNotNull(webAppServlet, "Web app servlet");
  		final String[] aliases = webAppServlet.getAliases();
  		if (aliases != null && aliases.length > 0) {
  			for (final String alias : aliases) {
  				try {
  					final Servlet servlet = newInstance(Servlet.class,
  							bundleClassLoader,
  							webAppServlet.getServletClassName());
  					httpService.registerServlet(alias, servlet,
  							convertInitParams(webAppServlet.getInitParams()),
  							httpContext);
  					//CHECKSTYLE:OFF
  				} catch (Throwable ignore) {
  					LOG.error("Registration exception. Skipping.", ignore);
  				}
  				//CHECKSTYLE:ON
  			}
  		} else {
  			LOG.warn("Servlet [" + webAppServlet
  					+ "] does not have any alias. Skipped.");
  		}
  	}
docs: Registers servlets with http context.
  
  @throws NullArgumentException if servlet is null
  @see WebAppVisitor#visit(WebAppServlet)