如何进一步停止处理请求？

如果请求中不存在某个标头，我需要阻止所有请求处理。所以，我有以下 SecurityConfig 代码，我在其中配置了一个在其他所有事情之前执行的过滤器：

protected void configure(HttpSecurity httpSecurity) throws Exception {
    httpSecurity.sessionManagement().sessionCreationPolicy(SessionCreationPolicy.STATELESS);
    
    httpSecurity.addFilterBefore(
        new OncePerRequestFilter() {
            @Override
            protected void doFilterInternal(HttpServletRequest request, HttpServletResponse response, FilterChain chain)
                    throws ServletException, IOException {    
                if(testmode) {
                    String testModeHeader = request.getHeader("TestMode");
                    System.out.println("In testmode :"+request.getRequestURI()+" "+testModeHeader);

                    if(!testmodeHeaderValue.equals(testModeHeader)) {
                        response.sendError(HttpServletResponse.SC_UNAUTHORIZED);
                        response.flushBuffer();
                        return;
                    }
                }
                chain.doFilter(request, response);
            }
        }
        , SecurityContextPersistenceFilter.class);
    
    httpSecurity.csrf().disable()
        .authorizeRequests().antMatchers("/oauth/**", "/oauth2/**").permitAll()
        .anyRequest().authenticated()
        .and()
        .oauth2Login()
        .userInfoEndpoint()
            .userService(oauthUserService)
        .and()
        .successHandler(new AuthenticationSuccessHandler() {
            
            @Override
            public void onAuthenticationSuccess(HttpServletRequest request, HttpServletResponse response, 
                    Authentication authentication) throws IOException, ServletException {
                ...code not shown...
            }
        })
        .and()
        .sessionManagement()
        .sessionCreationPolicy(SessionCreationPolicy.STATELESS);
}

尽管发送错误代码并使用flushBuffer提交响应，但似乎spring boot仍在将用户重定向到登录页面，如下输出所示：

In testmode :/token null
In testmode :/oauth2/authorization/google null
In testmode :/oauth2/authorization/google null
In testmode :/oauth2/authorization/google null
In testmode :/oauth2/authorization/google null
In testmode :/oauth2/authorization/google null
In testmode :/oauth2/authorization/google null
In testmode :/oauth2/authorization/google null
In testmode :/oauth2/authorization/google null
In testmode :/oauth2/authorization/google null
In testmode :/oauth2/authorization/google null
In testmode :/oauth2/authorization/google null
In testmode :/oauth2/authorization/google null
In testmode :/oauth2/authorization/google null
In testmode :/oauth2/authorization/google null
In testmode :/oauth2/authorization/google null
In testmode :/oauth2/authorization/google null
In testmode :/oauth2/authorization/google null

我需要做什么才能在不通过任何其余过滤器的情况下提交响应？

而且我不确定当我只向 /token 发出一个请求时，向 /oauth2/authorization/google 收到这么多请求是什么？