Fix memory leak

spring-boot-modules/spring-boot-keycloak/src/main/java/com/baeldung/keycloak/SecurityConfig.java

@@ -13,12 +13,14 @@ import org.springframework.security.config.annotation.web.configuration.EnableWe
 import org.springframework.security.core.GrantedAuthority;
 import org.springframework.security.core.authority.SimpleGrantedAuthority;
 import org.springframework.security.core.authority.mapping.GrantedAuthoritiesMapper;
+import org.springframework.security.core.session.SessionRegistry;
 import org.springframework.security.core.session.SessionRegistryImpl;
 import org.springframework.security.oauth2.core.oidc.user.OidcUserAuthority;
 import org.springframework.security.oauth2.core.user.OAuth2UserAuthority;
 import org.springframework.security.web.SecurityFilterChain;
 import org.springframework.security.web.authentication.session.RegisterSessionAuthenticationStrategy;
 import org.springframework.security.web.authentication.session.SessionAuthenticationStrategy;
+import org.springframework.security.web.session.HttpSessionEventPublisher;
 import org.springframework.security.web.util.matcher.AntPathRequestMatcher;
 
 @Configuration
@@ -35,9 +37,19 @@ class SecurityConfig {
         this.keycloakLogoutHandler = keycloakLogoutHandler;
     }
 
+    @Bean
+    public SessionRegistry sessionRegistry() {
+        return new SessionRegistryImpl();
+    }
+
     @Bean
     protected SessionAuthenticationStrategy sessionAuthenticationStrategy() {
-        return new RegisterSessionAuthenticationStrategy(new SessionRegistryImpl());
+        return new RegisterSessionAuthenticationStrategy(sessionRegistry());
+    }
+
+    @Bean
+    public HttpSessionEventPublisher httpSessionEventPublisher() {
+        return new HttpSessionEventPublisher();
     }