如果您有一个AuthenticationProvider，您可以将其注册为bean，Spring Security将拾取它：

@Bean
public CustomAuthenticationProvider customAuthenticationProvider() {
    return new CustomAuthenticationProvider();
}

或者，您可以在HttpSecurity配置中添加其他AuthenticationProvider：

@Bean
public SecurityFilterChain securityFilterChain(HttpSecurity http) throws Exception {
    http
        // ...
        .authenticationProvider(new CustomAuthenticationProvider());
    return http.build();
}

您可以使用**@EnableGlobalAuthentication**为配置类添加注解，并且能够配置AuthenticationManagerBuilder的全局示例：

@Autowired
   public void configureGlobal(AuthenticationManagerBuilder auth) {
      auth.authenticationProvider(customAuthenticationProvider);
   }

请参见相关文档：https://docs.spring.io/spring-security/site/docs/current/api/org/springframework/security/config/annotation/authentication/configuration/EnableGlobalAuthentication.html

当我想使用Spring Security添加一个自定义AuthenticationProvider而不使用WebSecurityConfigurerAdapter时，也遇到了同样的问题。
我是这么做的。
带有WebSecurityConfigurerAdapter的代码

public class SecurityConfiguration extends WebSecurityConfigurerAdapter { 

    ...

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

没有WebSecurityConfigurer适配器的代码

@EnableWebSecurity
@EnableGlobalAuthentication
public class SecurityConfiguration { 

        ...

        @Autowired
        CustomAuthenticationProvider customAuthenticationProvider;

        @Autowired
        void registerProvider(AuthenticationManagerBuilder auth) {
           auth.authenticationProvider(customAuthenticationProvider);
        }
    }

注意：@启用全局身份验证并注册提供者（）。
希望这会有所帮助。

我也遇到过类似的问题。我有一个自定义的用户详细信息服务，我还使用了一个额外的自定义身份验证提供程序。一个是针对实际用户的，而自定义提供程序是针对自动化设备的。
这是我的代码与WebSecurityConfigurerAdapter：

@Configuration
@EnableWebSecurity
@EnableGlobalMethodSecurity(prePostEnabled = true)
public class WebSecurityConfig extends WebSecurityConfigurerAdapter {

    ...

    @Autowired
    private MyCustomAuthenticationProvider customAuthenticationProvider;

    @Autowired
    private UserDetailsService userDetailsService;

    ...

    @Bean
    PasswordEncoder passwordEncoder() {
        return PasswordEncoderFactories.createDelegatingPasswordEncoder();
    }

    @Bean
    @Override
    public AuthenticationManager authenticationManagerBean() throws Exception {
        return super.authenticationManagerBean();
    }

    @Override
    public void configure(AuthenticationManagerBuilder auth) throws Exception {
        var encoder = passwordEncoder();
        customAuthenticationProvider.encoder(encoder);
        auth.userDetailsService(userDetailsService).passwordEncoder(encoder);
        auth.authenticationProvider(customAuthenticationProvider);
    }

    ...
}

这是我没有WebSecurityConfigurerAdapter的代码：

@Configuration
@EnableWebSecurity
@EnableGlobalMethodSecurity(prePostEnabled = true)
public class SecurityConfiguration {

    ...

    @Autowired
    private MyCustomAuthenticationProvider customAuthenticationProvider;

    @Autowired
    private UserDetailsService userDetailsService;

    ...

    @Bean
    PasswordEncoder passwordEncoder() {
        return PasswordEncoderFactories.createDelegatingPasswordEncoder();
    }

    @Bean
    AuthenticationManager authenticationManager(AuthenticationConfiguration authenticationConfiguration) throws Exception {
        return authenticationConfiguration.getAuthenticationManager();
    }

    @Autowired
    public void configureGlobal(AuthenticationManagerBuilder auth) throws Exception {
        var encoder = passwordEncoder();
        customAuthenticationProvider.encoder(encoder);
        auth.userDetailsService(userDetailsService).passwordEncoder(encoder);
        auth.authenticationProvider(customAuthenticationProvider);
    }

    ...

}

注意：您可能需要在您的属性文件中将spring.main.allow-circular-references设置为true，这样才能正常工作。