Authorization Events
对于每个被拒绝的授权，都会激发一个 AuthorizationDeniedEvent。此外，还可以为授予的授权激发 AuthorizationGrantedEvent。
若要侦听这些事件，必须首先发布 AuthorizationEventPublisher。
Spring Security 的 SpringAuthorizationEventPublisher 可能会做得很好。它使用 Spring 的 ApplicationEventPublisher 发布授权事件:
@Bean
public AuthorizationEventPublisher authorizationEventPublisher(ApplicationEventPublisher applicationEventPublisher) {return new SpringAuthorizationEventPublisher(applicationEventPublisher);
}
然后，您可以使用 Spring 的@EventListener 支持:
@Component
public class AuthenticationEvents {@EventListenerpublic void onFailure(AuthorizationDeniedEvent failure) {// ...}
}
Authorization Granted Events
因为 AuthorizationGrantedEvents 有可能非常嘈杂，所以默认情况下不发布它们。
事实上，发布这些事件可能需要您自己的一些业务逻辑，以确保应用程序不会被嘈杂的授权事件淹没。
您可以创建自己的事件发布者来筛选成功事件。例如，下面的发布者只在需要 ROLE _ ADMIN 的地方发布授权:
@Component
public class MyAuthorizationEventPublisher implements AuthorizationEventPublisher {private final ApplicationEventPublisher publisher;private final AuthorizationEventPublisher delegate;public MyAuthorizationEventPublisher(ApplicationEventPublisher publisher) {this.publisher = publisher;this.delegate = new SpringAuthorizationEventPublisher(publisher);}@Overridepublic <T> void publishAuthorizationEvent(Supplier<Authentication> authentication,T object, AuthorizationDecision decision) {if (decision == null) {return;}if (!decision.isGranted()) {this.delegate.publishAuthorizationEvent(authentication, object, decision);return;}if (shouldThisEventBePublished(decision)) {AuthorizationGrantedEvent granted = new AuthorizationGrantedEvent(authentication, object, decision);this.publisher.publishEvent(granted);}}private boolean shouldThisEventBePublished(AuthorizationDecision decision) {if (!(decision instanceof AuthorityAuthorizationDecision)) {return false;}Collection<GrantedAuthority> authorities = ((AuthorityAuthorizationDecision) decision).getAuthorities();for (GrantedAuthority authority : authorities) {if ("ROLE_ADMIN".equals(authority.getAuthority())) {return true;}}return false;}
}
