Spring Boot Keycloak - How to get a list of roles assigned to a user?

I am trying to get a list of roles assigned to a particular user from a Spring Boot application secured with keycloak.

I have declared an AccessToken bean in the KeycloakWebSecurityConfigurerAdapter configuration class as follows:

    @Configuration
    @EnableWebSecurity
    @ComponentScan(basePackageClasses = KeycloakSecurityComponents.class)
    public class KeycloakSecurityConfig extends KeycloakWebSecurityConfigurerAdapter {

//other config code

        @Bean
        @Scope(scopeName = WebApplicationContext.SCOPE_REQUEST, proxyMode = ScopedProxyMode.TARGET_CLASS)
        public AccessToken accessToken() {
            HttpServletRequest request = ((ServletRequestAttributes) RequestContextHolder.currentRequestAttributes()).getRequest();
            return ((KeycloakSecurityContext) ((KeycloakAuthenticationToken) request.getUserPrincipal()).getCredentials()).getToken();
        }

    }

Now I can autowire the AccessToken in the controller and I am able to get the information like ID and username but how do I get the list of roles assigned to the user using the AccessToken?