7. 로그인 처리2 - 필터, 인터셉터

public interface Filter {
    public default void init(FilterConfig filterConfig) throws ServletException {}
    public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException;
    public default void destroy() {}
}

@Slf4j
public class LogFilter implements Filter {
  
    @Override
    public void init(FilterConfig filterConfig) throws ServletException {
        log.info("log filter init");
    }
  
    @Override
    public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {
        HttpServletRequest httpRequest = (HttpServletRequest) request;
        String requestURI = httpRequest.getRequestURI();
      
        String uuid = UUID.randomUUID().toString();
        try {
            log.info("REQUEST [{}][{}]", uuid, requestURI);
            chain.doFilter(request, response);
        } catch (Exception e) {
            throw e;
        } finally {
            log.info("RESPONSE [{}][{}]", uuid, requestURI);
        }
    }
  
    @Override
    public void destroy() {
        log.info("log filter destroy");
    }
}

@Configuration
public class WebConfig {
  
    @Bean
    public FilterRegistrationBean logFilter() {
        FilterRegistrationBean<Filter> filterRegistrationBean = new FilterRegistrationBean<>();
        filterRegistrationBean.setFilter(new LogFilter());
        filterRegistrationBean.setOrder(1);
        filterRegistrationBean.addUrlPatterns("/*");
        return filterRegistrationBean;
    }
}

@Slf4j
public class LoginCheckFilter implements Filter {
  
    private static final String[] whitelist = {"/", "/members/add", "/login","/logout","/css/*"};
  
    @Override
    public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {
        HttpServletRequest httpRequest = (HttpServletRequest) request;
        String requestURI = httpRequest.getRequestURI();
      
        HttpServletResponse httpResponse = (HttpServletResponse) response;
      
        try {
            log.info("인증 체크 필터 시작 {}", requestURI);

            if (isLoginCheckPath(requestURI)) {
                log.info("인증 체크 로직 실행 {}", requestURI);
                HttpSession session = httpRequest.getSession(false);
                if (session == null || session.getAttribute(SessionConst.LOGIN_MEMBER) == null) {
                    log.info("미인증 사용자 요청 {}", requestURI);
                    //로그인으로 redirect
                    httpResponse.sendRedirect("/login?redirectURL=" + requestURI);

                    return; //여기가 중요, 미인증 사용자는 다음으로 진행하지 않고 끝!
                }
            }
            chain.doFilter(request, response);
        } catch (Exception e) {
            throw e; //예외 로깅 가능 하지만, 톰캣까지 예외를 보내주어야 함
        } finally {
            log.info("인증 체크 필터 종료 {}", requestURI);
        }
    }
  
    /**
    * 화이트 리스트의 경우 인증 체크X
    */
    private boolean isLoginCheckPath(String requestURI) {
        return !PatternMatchUtils.simpleMatch(whitelist, requestURI);
    }
}

@Bean
public FilterRegistrationBean loginCheckFilter() {
    FilterRegistrationBean<Filter> filterRegistrationBean = new FilterRegistrationBean<>();
    filterRegistrationBean.setFilter(new LoginCheckFilter());
    filterRegistrationBean.setOrder(2);
    filterRegistrationBean.addUrlPatterns("/*");
    return filterRegistrationBean;
}

/**
* 로그인 이후 redirect 처리
*/
@PostMapping("/login")
public String loginV4(
  @Valid @ModelAttribute LoginForm form, BindingResult bindingResult,
  @RequestParam(defaultValue = "/") String redirectURL,
  HttpServletRequest request) {
  
    if (bindingResult.hasErrors()) {
        return "login/loginForm";
    }
  
    Member loginMember = loginService.login(form.getLoginId(), form.getPassword());
    log.info("login? {}", loginMember);
  
    if (loginMember == null) {
        bindingResult.reject("loginFail", "아이디 또는 비밀번호가 맞지 않습니다.");
        return "login/loginForm";
    }
  
    //로그인 성공 처리
  
    //세션이 있으면 있는 세션 반환, 없으면 신규 세션 생성
    HttpSession session = request.getSession();
    //세션에 로그인 회원 정보 보관
    session.setAttribute(SessionConst.LOGIN_MEMBER, loginMember);
  
    //redirectURL 적용
    return "redirect:" + redirectURL;
}

public interface HandlerInterceptor {
    default boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {}
    default void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, @Nullable ModelAndView modelAndView) throws Exception {}
    default void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, @Nullable Exception ex) throws Exception {}
}

@Slf4j
public class LogInterceptor implements HandlerInterceptor {
  
    public static final String LOG_ID = "logId";
  
    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
      
        String requestURI = request.getRequestURI();
      
        String uuid = UUID.randomUUID().toString();
        request.setAttribute(LOG_ID, uuid);
      
        //@RequestMapping: HandlerMethod
        //정적 리소스: ResourceHttpRequestHandler
        if (handler instanceof HandlerMethod) {
            HandlerMethod hm = (HandlerMethod) handler; //호출할 컨트롤러 메서드의 모든 정보가 포함되어 있다.
        }
      
        log.info("REQUEST [{}][{}][{}]", uuid, requestURI, handler);
        return true; //false 진행X
    }
  
    @Override
    public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView) throws Exception {
        log.info("postHandle [{}]", modelAndView);
    }
  
    @Override
    public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) throws Exception {
        String requestURI = request.getRequestURI();
        String logId = (String)request.getAttribute(LOG_ID);
        log.info("RESPONSE [{}][{}]", logId, requestURI);
        if (ex != null) {
            log.error("afterCompletion error!!", ex);
        }
    }
}

if (handler instanceof HandlerMethod) {
    HandlerMethod hm = (HandlerMethod) handler; //호출할 컨트롤러 메서드의 모든 정보가 포함되어 있다.
}

@Configuration
public class WebConfig implements WebMvcConfigurer {
  
    @Override
    public void addInterceptors(InterceptorRegistry registry) {
        registry.addInterceptor(new LogInterceptor())
          .order(1)
          .addPathPatterns("/**")
          .excludePathPatterns("/css/**", "/*.ico", "/error");
    }
    //...
}

@Slf4j
public class LoginCheckInterceptor implements HandlerInterceptor {
  
    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
      
        String requestURI = request.getRequestURI();

        log.info("인증 체크 인터셉터 실행 {}", requestURI);
        HttpSession session = request.getSession(false);

        if (session == null || session.getAttribute(SessionConst.LOGIN_MEMBER) == null) {
            log.info("미인증 사용자 요청");
            //로그인으로 redirect
            response.sendRedirect("/login?redirectURL=" + requestURI);
            return false;
        }
        return true;
    }
}

@Configuration
public class WebConfig implements WebMvcConfigurer {
  
    @Override
    public void addInterceptors(InterceptorRegistry registry) {
        registry.addInterceptor(new LogInterceptor())
            .order(1)
            .addPathPatterns("/**")
            .excludePathPatterns("/css/**", "/*.ico", "/error");

        registry.addInterceptor(new LoginCheckInterceptor())
            .order(2)
            .addPathPatterns("/**")
            .excludePathPatterns(
                "/", "/members/add", "/login", "/logout",
                "/css/**", "/*.ico", "/error"
            );
    }
    //...
}

@GetMapping("/")
public String homeLoginV3ArgumentResolver(@Login Member loginMember, Modelmodel) {
  
    //세션에 회원 데이터가 없으면 home
    if (loginMember == null) {
        return "home";
    }
  
    //세션이 유지되면 로그인으로 이동
    model.addAttribute("member", loginMember);
    return "loginHome";
}

@Target(ElementType.PARAMETER)
@Retention(RetentionPolicy.RUNTIME)
public @interface Login {
}

@Slf4j
public class LoginMemberArgumentResolver implements
HandlerMethodArgumentResolver {
  
    @Override
    public boolean supportsParameter(MethodParameter parameter) {
      
        log.info("supportsParameter 실행");
      
        boolean hasLoginAnnotation =        parameter.hasParameterAnnotation(Login.class);
        boolean hasMemberType = Member.class.isAssignableFrom(parameter.getParameterType());
      
        return hasLoginAnnotation && hasMemberType;
    }
  
    @Override
    public Object resolveArgument(MethodParameter parameter, ModelAndViewContainer mavContainer, NativeWebRequest webRequest, WebDataBinderFactory binderFactory) throws Exception {
      
      //  log.info("resolveArgument 실행");

        HttpServletRequest request = (HttpServletRequest) webRequest.getNativeRequest();
        HttpSession session = request.getSession(false);
        if (session == null) {
            return null;
        }

        return session.getAttribute(SessionConst.LOGIN_MEMBER);
    }
}

@Configuration
public class WebConfig implements WebMvcConfigurer {
  
    @Override
    public void addArgumentResolvers(List<HandlerMethodArgumentResolver> resolvers) {
        resolvers.add(new LoginMemberArgumentResolver());
    }
    //...
}