Using Spring Security for authentication and authorization

This web application has used Spring Security for authentication of users and to authorize them to submit comments. The Maven Spring Security starter needs to be specified, as follows, to enable Spring Security in the web application:

<dependencies>
   <dependency>
      <groupId>org.springframework.boot</groupId>
      <artifactId>spring-boot-starter-security</artifactId>
   </dependency>
   <dependency>
      <groupId>org.springframework.security</groupId>
      <artifactId>spring-security-webflux</artifactId>
      <version>5.0.0.M2</version>
   </dependency>
</dependencies>

The following is the Spring Security configuration:

@Configuration
@EnableWebFluxSecurity
@EnableReactiveMethodSecurity
public class SecurityConfig {

@Autowired
private UserService userService;

@Bean
public SecurityWebFilterChain 
    springWebFilterChain(ServerHttpSecurity...