我基于UsernamePasswordAuthenticationFilter需要的自定義過濾器，AuthenticationManager但每次我調用該方法時，attemptAuthentication()編譯都會在這里失敗：Authentication auth2 = this.getAuthenticationManager().authenticate(authRequest);為AuthenticationManager空：java.lang.NullPointerException: null    at app.shellx.security.CustomUsernamePasswordAuthenticationFilter.attemptAuthentication(CustomUsernamePasswordAuthenticationFilter.java:75) ~[classes/:na]Web安全配置@Configuration@EnableWebSecurity@EnableGlobalMethodSecurity(securedEnabled = true)public class WebSecurityConfig extends WebSecurityConfigurerAdapter {    @Autowired    UserService userService;    @Autowired    private JwtTokenFilter jwtTokenFilter;    @Autowired    private CustomAuthenticationSuccessHandler customAuthenticationSuccessHandler;    @Override    protected void configure(HttpSecurity http) throws Exception {        http            .httpBasic().disable()            .addFilterBefore(jwtTokenFilter, UsernamePasswordAuthenticationFilter.class)            .sessionManagement()            .sessionCreationPolicy(SessionCreationPolicy.STATELESS)                .and()            .cors().and()            .csrf().disable()            .authorizeRequests() // .antMatchers("/**")                .antMatchers("/login/**", "/register/**").permitAll()                .antMatchers("/admin/**").hasRole("ADMIN")                      .anyRequest().authenticated()                .and()            //.csrfTokenRepository(CookieCsrfTokenRepository.withHttpOnlyFalse());            .addFilterAt(new CustomUsernamePasswordAuthenticationFilter(), UsernamePasswordAuthenticationFilter.class)              .formLogin()                .loginPage("http://localhost:4200/login")//.failureUrl("/login-error")                .loginProcessingUrl("/login")                 .usernameParameter("email")                .successHandler(customAuthenticationSuccessHandler)                .and()            .logout()                 .permitAll();    }