여기서 왜 401 ERROR 가 발생하는지 잘 모르겠습니다.

안녕하세요. 강의 매우 잘 듣고 있습니다.

다름이 아니라 질문이 있는데요.

시큐리티 설정은 이렇게 해주고, ajax.http 실행시켜주면

HTTP/1.1 401 

X-Content-Type-Options: nosniff

X-XSS-Protection: 1; mode=block

Cache-Control: no-cache, no-store, max-age=0, must-revalidate

Pragma: no-cache

Expires: 0

X-Frame-Options: DENY

Content-Length: 0

Date: Sat, 05 Feb 2022 13:50:25 GMT

Keep-Alive: timeout=60

Connection: keep-alive

<Response body is empty>

Response code: 401; Time: 4ms; Content length: 0 bytes

401 에러가 발생하는데 어디쪽을 확인하면 좋을까요..?

AjaxSecurityConfig

@Order(0)
@Configuration
public class AjaxSecurityConfig extends WebSecurityConfigurerAdapter {


    @Override
    protected void configure(AuthenticationManagerBuilder auth) throws Exception {
        auth.authenticationProvider(ajaxAuthenticationProvider());
    }

    @Bean
    public AuthenticationProvider ajaxAuthenticationProvider() {
        return new AjaxAuthenticationProvider();
    }

    @Bean
    public AuthenticationSuccessHandler ajaxAuthenticationSuccessHandler() {
        return new AjaxAuthenticationSuccessHandler();
    }

    @Bean
    public AuthenticationFailureHandler ajaxAuthenticationFailureHandler() {
        return new AjaxAuthenticationFailureHandler();
    }

    @Override
    protected void configure(HttpSecurity http) throws Exception {
        http
                .antMatcher("/api/**")
                .authorizeRequests()
                .antMatchers("/api/messages").hasRole("MANAGER")
                .anyRequest().authenticated()
                .and()
                .addFilterBefore(ajaxLoginProcessingFilter(), UsernamePasswordAuthenticationFilter.class)
        ;

        http
                .exceptionHandling()
                .authenticationEntryPoint(new AjaxLoginAuthenticationEntryPoint())
                .accessDeniedHandler(ajaxAccessDeniedHandler())
        ;

        http.csrf().disable();
    }
    @Bean
    public AccessDeniedHandler ajaxAccessDeniedHandler() {
        return new AjaxAccessDeniedHandler();
    }

    @Bean
    public AjaxLoginProcessingFilter ajaxLoginProcessingFilter() throws Exception {
        AjaxLoginProcessingFilter filter = new AjaxLoginProcessingFilter();
        filter.setAuthenticationManager(authenticationManagerBean());
        filter.setAuthenticationSuccessHandler(ajaxAuthenticationSuccessHandler());
        filter.setAuthenticationFailureHandler(ajaxAuthenticationFailureHandler());
        return filter;
    }
}