如何在Spring Security reactive应用程序中以编程方式设置Authentication对象？

@Configuration
@EnableWebFluxSecurity
public class SecurityConfig {

    @Bean
    public SecurityWebFilterChain securityFilterChain(ServerHttpSecurity http) {
        return http
            .authorizeExchange()
                .anyExchange().authenticated()
                .and()
            .httpBasic()
                .and()
            .authenticationManager(authenticationManager())
                .securityContextRepository(NoOpServerSecurityContextRepository.getInstance())
                .csrf().disable()
                .build();
    }

    @Bean
    public ReactiveAuthenticationManager authenticationManager() {
        return authentication -> {
            String username = authentication.getPrincipal().toString();
            String password = authentication.getCredentials().toString();

            // 自定义认证逻辑，验证用户名和密码
            // ...

            // 验证成功后返回认证对象
            Authentication authenticated = new UsernamePasswordAuthenticationToken(username, password, new ArrayList<>());
            return Mono.just(authenticated);
        };
    }

    @Bean
    public ServerAuthenticationEntryPoint authenticationEntryPoint() {
        return (exchange, e) -> Mono.fromRunnable(() -> {
            exchange.getResponse().setStatusCode(HttpStatus.UNAUTHORIZED);
        });
    }
}