Entendimento do fluxo

package br.com.alura.gerenciador.servlet;

import java.io.IOException;
import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.annotation.WebFilter;
import javax.servlet.http.HttpFilter;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;



public class AutorizacaoFilter extends HttpFilter implements Filter {



    /**
     * @see Filter#doFilter(ServletRequest, ServletResponse, FilterChain)
     */
    public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain chain) throws IOException, ServletException {

        System.out.println("Autorização filter");

        HttpServletRequest request = (HttpServletRequest) servletRequest;
        HttpServletResponse response = (HttpServletResponse) servletResponse;



        String paramAcao = request.getParameter("acao");    

        HttpSession sessao = request.getSession();
        boolean usuarioNaoEstaLogado =sessao.getAttribute("usuarioLogado") == null;
        boolean ehUmaAcaoProtegida = !(paramAcao.equals("Login")||paramAcao.equals("loginForm"));


        if(ehUmaAcaoProtegida && usuarioNaoEstaLogado) {
           response.sendRedirect("entrada?acao=loginForm");
          return;

        }

        chain.doFilter(request, response);
    }



}

package br.com.alura.gerenciador.servlet;

import java.io.IOException;

import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.annotation.WebFilter;



public class MonitoramentoFilter implements Filter {

    @Override
    public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain)
            throws IOException, ServletException {



long antes=System.currentTimeMillis();

System.out.println("Monitoramento Filter");

String acao =request.getParameter("acao");


System.out.println("Entrando no Chain");        


chain.doFilter(request, response);    

System.out.println("Saindo do chain");




long depois=System.currentTimeMillis();

System.out.println("Tempo de execução da acao  : "+acao+ "->'" + (depois-antes));

    }





}

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://xmlns.jcp.org/xml/ns/javaee" xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_4_0.xsd" id="WebApp_ID" version="4.0">
  <display-name>gerenciador</display-name>
  <welcome-file-list>
    <welcome-file>bem-vindo.html</welcome-file>
  </welcome-file-list>
  <servlet>
    <servlet-name>OiMundoServlet</servlet-name>
    <servlet-class>br.com.alura.gerenciador.servlet.OiMundoServlet</servlet-class>
  </servlet>
  <servlet-mapping>
    <servlet-name>OiMundoServlet</servlet-name>
    <url-pattern>/ola</url-pattern>
  </servlet-mapping>
  <filter>
    <filter-name>MF</filter-name>
    <filter-class>br.com.alura.gerenciador.servlet.MonitoramentoFilter</filter-class>
</filter>

<filter-mapping>
    <filter-name>MF</filter-name>
    <url-pattern>/entrada</url-pattern>
</filter-mapping>
  <filter>
    <filter-name>AF</filter-name>
    <filter-class>br.com.alura.gerenciador.servlet.AutorizacaoFilter</filter-class>
</filter>

<filter-mapping>
    <filter-name>AF</filter-name>
    <url-pattern>/entrada</url-pattern>
</filter-mapping>
<filter>
    <filter-name>CF</filter-name>
    <filter-class>br.com.alura.gerenciador.servlet.ControladorFilter</filter-class>
</filter>

<filter-mapping>
    <filter-name>CF</filter-name>
    <url-pattern>/entrada</url-pattern>
</filter-mapping>
</web-app>

Meus filtros ficaram iguais ao que foi proposto em aula , entretanto acrescentei "entrando no chain" e "Saindo do chain" pois não ficou muito claro o fluxo que é feito quando se saí "abruptamente" com o return em :

    if(ehUmaAcaoProtegida && usuarioNaoEstaLogado) {
           response.sendRedirect("entrada?acao=loginForm");
          return;

        }