Springboot Actuator之十：actuator中的audit包

前言
这篇文章我们来分析一下org.springframework.boot.actuate.security,org.springframework.boot.actuate.audit中的代码,这2个包的类是对spring security 的事件进行处理的.类图如下:

二、源码解析

2.1、AuditEvent事件类

AuditEvent–> 1个值对象–>代表了1个audit event: 在特定的时间,1个特定的用户或者代理,实施了1个特定类型的动作.AuditEvent记录了有关AuditEvent的细节.

其类上有如下注解:

@JsonInclude(Include.NON_EMPTY)

代表该类中为空(“”)或者为null的属性不会被序列化。

该类的字段如下:

private final Date timestamp;

// 资源
private final String principal;

private final String type;

private final Map<String, Object> data;

2.2、AuditApplicationEvent事件类

AuditApplicationEvent–> 封装AuditEvent.代码如下:

public class AuditApplicationEvent extends ApplicationEvent {

    private final AuditEvent auditEvent;

    public AuditApplicationEvent(String principal, String type,
            Map<String, Object> data) {
        this(new AuditEvent(principal, type, data));
    }

    AuditApplicationEvent(String principal, String type, String... data) {
        this(new AuditEvent(principal, type, data));
    }

    public AuditApplicationEvent(Date timestamp, String principal, String type,
            Map<String, Object> data) {
        this(new AuditEvent(timestamp, principal, type, data));
    }

    public AuditApplicationEvent(AuditEvent auditEvent) {
        super(auditEvent);
        Assert.notNull(auditEvent, "AuditEvent must not be null");
        this.auditEvent = auditEvent;
    }

    public AuditEvent getAuditEvent() {
        return this.auditEvent;
    }

}

2.3、AbstractAuditListener

AbstractAuditListener –>处理AuditApplicationEvent事件的抽象类.代码如下:

public abstract class AbstractAuditListener
        implements ApplicationListener<AuditApplicationEvent> {

    @Override
    public void onApplicationEvent(AuditApplicationEvent event) {
        onAuditEvent(event.getAuditEvent());
    }

    protected abstract void onAuditEvent(AuditEvent event);

}

2.4、AuditEventRepository

AuditEventRepository–> 关于AuditEvent的dao实现.声明了如下4个方法:

// 添加日志
void add(AuditEvent event);

// 查询指定日期之后的AuditEvent
List<AuditEvent> find(Date after);

// 根据给定的Date和principal(资源)获得对应的AuditEvent
List<AuditEvent> find(String principal, Date after);

// 根据给的date,principal,type 类获取给定的AuditEvent
List<AuditEvent> find(String principal, Date after, String type);

2.5、InMemoryAuditEventRepository

InMemoryAuditEventRepository –> AuditEventRepository接口的唯一实现.

该类的字段如下:

// AuditEvent数组默认的默认大小
private static final int DEFAULT_CAPACITY = 4000;

// 用于对events进行操作时 加的锁
private final Object monitor = new Object();

/**
* Circular buffer of the event with tail pointing to the last element.
* 循环数组
*/
private AuditEvent[] events;

// 最后1个元素的下标
private volatile int tail = -1;

构造器如下:

public InMemoryAuditEventRepository() {
   this(DEFAULT_CAPACITY);
}

public InMemoryAuditEventRepository(int capacity) {
   this.events = new AuditEvent[capacity];
}

AuditEventRepository中的方法实现如下:

    @Override
    public void add(AuditEvent event) {
        Assert.notNull(event, "AuditEvent must not be null");
        synchronized (this.monitor) {
            this.tail = (this.tail + 1) % this.events.length;
            this.events[this.tail] = event;
        }
    }

    @Override
    public List<AuditEvent> find(Date after) {
        return find(null, after, null);
    }

    @Override
    public List<AuditEvent> find(String principal, Date after) {
        return find(principal, after, null);
    }
    //上面两个方法最终调用这个方法
    @Override
    public List<AuditEvent> find(String principal, Date after, String type) {
        LinkedList<AuditEvent> events = new LinkedList<AuditEvent>();
        synchronized (this.monitor) {
        // 1. 遍历events
        for (int i = 0; i < this.events.length; i++) {
            // 1.1 获得最新的AuditEvent
            AuditEvent event = resolveTailEvent(i);
            // 1.2 如果AuditEvent 不等于null并且符合查询要求的话,就加入到events中
            if (event != null && isMatch(principal, after, type, event)) {
                events.addFirst(event);
            }
        }
    }
        // 2. 返回结果集
        return events;
    }

    //过滤不和条件的事件
    private boolean isMatch(String principal, Date after, String type, AuditEvent event) {
        boolean match = true;
        match = match && (principal == null || event.getPrincipal().equals(principal));
        match = match && (after == null || event.getTimestamp().compareTo(after) >= 0);
        match = match && (type == null || event.getType().equals(type));
        return match;
    }

    //获得最新的AuditEvent
    private AuditEvent resolveTailEvent(int offset) {
        int index = ((this.tail + this.events.length - offset) % this.events.length);
        return this.events[index];
    }

返回结果集

这里有2个问题:

　　1、前面说过访问events的时候都需要进行加锁,为什么resolveTailEvent方法没有加锁?

　　　　原因如下: resolveTailEvent的调用点只有1个,就是在find(String Date , String)中,而在该方法中已经加锁了,因此该方法不需要加锁.

　　2、resolveTailEvent方法加锁可以吗

　　　　答: 可以,原因是synchronized 是可重入的.但是不推荐,如果加上,会产生性能损耗.

关于这个方法的实现原理我们还是举个例子比较好.假设我们的数组长度为3个,此时已经放满数组了,如下:

[0,1,2]

此时tail = 2, 然后我们继续放入3,则数组如下:

[3,1,2],此时tail = 0. 然后我们调用find.在该方法中会调用resolveTailEvent.

第1次传入的是0,则index = (0+3-0)%3 = 0,获得的正是3.
第2次传入的是1,则index = (0+3-1)%3 = 2,获得的正是2.
第3次传入的是2,则index = (0+3-2)%3 = 1,获得的正是1.
因此说find(String, Date, String)获得的结果时按照添加的顺序倒序返回的.

自动装配:

声明在AuditAutoConfiguration类内的static AuditEventRepositoryConfiguration配置类中,代码如下:

@ConditionalOnMissingBean(AuditEventRepository.class)
protected static class AuditEventRepositoryConfiguration {

    @Bean
    public InMemoryAuditEventRepository auditEventRepository() throws Exception {
        return new InMemoryAuditEventRepository();
    }

}

当beanFactory中不存在 AuditEventRepository类型的bean时生效.注册1个id为auditEventRepository,类型为InMemoryAuditEventRepository的bean.

2.6、AuditListener

AuditListener–> AbstractAuditListener的默认实现.监听AuditApplicationEvent事件然后存储到AuditEventRepository中. 代码如下:

public class AuditListener extends AbstractAuditListener {

    private static final Log logger = LogFactory.getLog(AuditListener.class);

    private final AuditEventRepository auditEventRepository;

    public AuditListener(AuditEventRepository auditEventRepository) {
        this.auditEventRepository = auditEventRepository;
    }

    @Override
    protected void onAuditEvent(AuditEvent event) {
        if (logger.isDebugEnabled()) {
            logger.debug(event);
        }
        this.auditEventRepository.add(event);
    }

}

监听到AuditApplicationEvent时,直接将其封装的AuditEvent加入到AuditEventRepository中.还是比较简单的.

自动装配如下:

在AuditAutoConfiguration中进行了声明,代码如下:

    @Bean
    @ConditionalOnMissingBean(AbstractAuditListener.class)
    public AuditListener auditListener() throws Exception {
        return new AuditListener(this.auditEventRepository);
    }

@Bean–> 注册1个id为auditListener,类型为AuditListener的bean
@ConditionalOnMissingBean(AbstractAuditListener.class) –> 当beanFactory中不存在类型为AbstractAuditListener的bean时生效。

注意,在AuditListener中注入的是InMemoryAuditEventRepository

2.7AbstractAuthenticationAuditListener

AbstractAuthenticationAuditListener–> 暴露 Spring Security AbstractAuthenticationEvent(认证事件) 将其转换为AuditEvent 的抽象ApplicationListener基类.

代码如下:

public abstract class AbstractAuthenticationAuditListener implements
    ApplicationListener<AbstractAuthenticationEvent>, ApplicationEventPublisherAware {

    private ApplicationEventPublisher publisher;

    @Override
    public void setApplicationEventPublisher(ApplicationEventPublisher publisher) {
        this.publisher = publisher;
    }

    protected ApplicationEventPublisher getPublisher() {
        return this.publisher;
    }

    protected void publish(AuditEvent event) {
        if (getPublisher() != null) {
            getPublisher().publishEvent(new AuditApplicationEvent(event));
        }
    }
}

2.8、AuthenticationAuditListener

AuthenticationAuditListener的默认实现
字段如下:

// 当发生AuthenticationSuccessEvent事件时添加到AuditEvent中的type
public static final String AUTHENTICATION_SUCCESS = "AUTHENTICATION_SUCCESS";

// 当发生AbstractAuthenticationFailureEvent事件时添加到AuditEvent中的type
public static final String AUTHENTICATION_FAILURE = "AUTHENTICATION_FAILURE";

// 当发生AuthenticationSwitchUserEvent事件时添加到AuditEvent中的type
public static final String AUTHENTICATION_SWITCH = "AUTHENTICATION_SWITCH";

private static final String WEB_LISTENER_CHECK_CLASS = "org.springframework.security.web.authentication.switchuser.AuthenticationSwitchUserEvent";

private WebAuditListener webListener = maybeCreateWebListener();

// 只要加入spring-boot-starter-security的依赖,就会在当前类路径下存在org.springframework.security.web.authentication.switchuser.AuthenticationSwitchUserEvent
// 因此会返回WebAuditListener
private static WebAuditListener maybeCreateWebListener() {
if (ClassUtils.isPresent(WEB_LISTENER_CHECK_CLASS, null)) {
return new WebAuditListener();
}
return null;
}

onApplicationEvent 方法实现如下:

public void onApplicationEvent(AbstractAuthenticationEvent event) {
    // 1. 如果验证失败,
    if (event instanceof AbstractAuthenticationFailureEvent) {
        onAuthenticationFailureEvent((AbstractAuthenticationFailureEvent) event);
    }
    // 2.如果webListener不等于null.并且该事件为AuthenticationSwitchUserEvent
    else if (this.webListener != null && this.webListener.accepts(event)) {
        this.webListener.process(this, event);
    }
    // 3. 如果是AuthenticationSuccessEvent
    else if (event instanceof AuthenticationSuccessEvent) {
        onAuthenticationSuccessEvent((AuthenticationSuccessEvent) event);
    }
}

　　1、如果验证失败(AbstractAuthenticationFailureEvent),则发送AuditEvent事件,其type为AUTHENTICATION_FAILURE.代码如下:

private void onAuthenticationFailureEvent(AbstractAuthenticationFailureEvent event) {
    Map<String, Object> data = new HashMap<String, Object>();
    data.put("type", event.getException().getClass().getName());
    data.put("message", event.getException().getMessage());
    if (event.getAuthentication().getDetails() != null) {
        data.put("details", event.getAuthentication().getDetails());
    }
    publish(new AuditEvent(event.getAuthentication().getName(),
            AUTHENTICATION_FAILURE, data));
}

　　2、如果webListener不等于null.并且该事件为AuthenticationSwitchUserEvent,则发送AuditEvent事件,其type为AUTHENTICATION_SWITCH.代码如下:

public void process(AuthenticationAuditListener listener,
        AbstractAuthenticationEvent input) {
    if (listener != null) {
        AuthenticationSwitchUserEvent event = (AuthenticationSwitchUserEvent) input;
        Map<String, Object> data = new HashMap<String, Object>();
        if (event.getAuthentication().getDetails() != null) {
            data.put("details", event.getAuthentication().getDetails());
        }
        data.put("target", event.getTargetUser().getUsername());
        listener.publish(new AuditEvent(event.getAuthentication().getName(),
                AUTHENTICATION_SWITCH, data));
    }

}

　　3、如果是AuthenticationSuccessEvent,则发送AuditEvent事件,其type为AUTHENTICATION_SUCCESS.代码如下:

private void onAuthenticationSuccessEvent(AuthenticationSuccessEvent event) {
    Map<String, Object> data = new HashMap<String, Object>();
    if (event.getAuthentication().getDetails() != null) {
        data.put("details", event.getAuthentication().getDetails());
    }
    publish(new AuditEvent(event.getAuthentication().getName(),
            AUTHENTICATION_SUCCESS, data));
}

自动装配:

在AuditAutoConfiguration中进行了声明,代码如下:

@Bean
@ConditionalOnClass(name = "org.springframework.security.authentication.event.AbstractAuthenticationEvent")
@ConditionalOnMissingBean(AbstractAuthenticationAuditListener.class)
public AuthenticationAuditListener authenticationAuditListener() throws Exception {
    return new AuthenticationAuditListener();
}

　　1、@Bean –> 注册1个id为authenticationAuditListener, AuthenticationAuditListener的bean

　　2、@ConditionalOnClass(name = “org.springframework.security.authentication.event.AbstractAuthenticationEvent”)–> 当在当前类路径下存在org.springframework.security.authentication.event.AbstractAuthenticationEvent时生效
　　3、@ConditionalOnMissingBean(AbstractAuthenticationAuditListener.class)–>beanFactory中不存在AbstractAuthenticationAuditListener类型的bean时生效.

2.9、AbstractAuthorizationAuditListener

AbstractAuthorizationAuditListener –>1个暴露AbstractAuthorizationEvent(授权事件)作为AuditEvent的抽象ApplicationListener基类.代码如下:

public abstract class AbstractAuthorizationAuditListener implements
        ApplicationListener<AbstractAuthorizationEvent>, ApplicationEventPublisherAware {

    private ApplicationEventPublisher publisher;

    @Override
    public void setApplicationEventPublisher(ApplicationEventPublisher publisher) {
        this.publisher = publisher;
    }

    protected ApplicationEventPublisher getPublisher() {
        return this.publisher;
    }

    protected void publish(AuditEvent event) {
        if (getPublisher() != null) {
            getPublisher().publishEvent(new AuditApplicationEvent(event));
        }
    }

}

2.10、AuthorizationAuditListener

AuthorizationAuditListener–> AbstractAuthorizationAuditListener的默认实现
字段如下:

// 发生AuthorizationFailureEvent事件时对应的AuditEvent的类型
public static final String AUTHORIZATION_FAILURE = "AUTHORIZATION_FAILURE";

onApplicationEvent代码如下:

public void onApplicationEvent(AbstractAuthorizationEvent event) {
    // 1. 如果是AuthenticationCredentialsNotFoundEvent事件,则发送AuditEvent事件,type为AUTHENTICATION_FAILURE
    if (event instanceof AuthenticationCredentialsNotFoundEvent) {
        onAuthenticationCredentialsNotFoundEvent(
                (AuthenticationCredentialsNotFoundEvent) event);
    }
    // 2. 如果是AuthorizationFailureEvent事件,则发送AuditEvent事件,type为AUTHORIZATION_FAILURE
    else if (event instanceof AuthorizationFailureEvent) {
        onAuthorizationFailureEvent((AuthorizationFailureEvent) event);
    }
}

　　1、如果是AuthenticationCredentialsNotFoundEvent事件,则发送AuditEvent事件,type为AUTHENTICATION_FAILURE.代码如下:

private void onAuthenticationCredentialsNotFoundEvent(
        AuthenticationCredentialsNotFoundEvent event) {
    Map<String, Object> data = new HashMap<String, Object>();
    data.put("type", event.getCredentialsNotFoundException().getClass().getName());
    data.put("message", event.getCredentialsNotFoundException().getMessage());
    publish(new AuditEvent("<unknown>",
            AuthenticationAuditListener.AUTHENTICATION_FAILURE, data));
}

　　2、如果是AuthorizationFailureEvent事件,则发送AuditEvent事件,type为AUTHORIZATION_FAILURE.代码如下:

private void onAuthorizationFailureEvent(AuthorizationFailureEvent event) {
    Map<String, Object> data = new HashMap<String, Object>();
    data.put("type", event.getAccessDeniedException().getClass().getName());
    data.put("message", event.getAccessDeniedException().getMessage());
    if (event.getAuthentication().getDetails() != null) {
        data.put("details", event.getAuthentication().getDetails());
    }
    publish(new AuditEvent(event.getAuthentication().getName(), AUTHORIZATION_FAILURE,
            data));
}

自动装配:

在AuditAutoConfiguration中进行了装配,代码如下:

@Bean
@ConditionalOnClass(name = "org.springframework.security.access.event.AbstractAuthorizationEvent")
@ConditionalOnMissingBean(AbstractAuthorizationAuditListener.class)
public AuthorizationAuditListener authorizationAuditListener() throws Exception {
    return new AuthorizationAuditListener();
}

1. @Bean –> 注册1个id为authorizationAuditListener,类型为AuthorizationAuditListener的bean
2. @ConditionalOnClass(name = “org.springframework.security.access.event.AbstractAuthorizationEvent”)–> 在当前类路径下存在org.springframework.security.access.event.AbstractAuthorizationEvent时生效
3. @ConditionalOnMissingBean(AbstractAuthorizationAuditListener.class)–> beanFactory中不存在AbstractAuthorizationAuditListener类型的bean时生效.

三、流程分析

准备工作
如果想让 spring boot 应用激活AuditEvent的事件的处理,需要加入spring-boot-starter-security依赖,代码如下:

<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-security</artifactId>
</dependency>

光加入依赖还不够,我们需要加入security的配置,不然AuthorizationAuditListener,AuthenticationAuditListener 监听什么事件呢? 因此,我们加入如下代码:

@Configuration
@EnableWebSecurity
public class WebSecurityConfig extends WebSecurityConfigurerAdapter {

    @Override
    protected void configure(HttpSecurity http) throws Exception {
        http.authorizeRequests().antMatchers("/error-log").hasAuthority("ROLE_TEST").antMatchers("/", "/home")
                .permitAll().anyRequest().authenticated().and().formLogin().loginPage("/login").permitAll().and()
                .logout().logoutUrl("/logout").permitAll().and().authorizeRequests();

    }

    @Autowired
    public void configureGlobal(AuthenticationManagerBuilder auth) throws Exception {
        auth.inMemoryAuthentication().withUser("user").password("password").roles("USER");
    }
}

在configureGlobal中,我们在内存中生成了1个用户:用户名为user,密码为password,角色为USER.
在configure中我们配置了如下内容:

1. 访问/error-log需要拥有ROLE_TEST的权限
2. 访问/,/home不需要进行验证
3. 登录页面为/login,不需要进行验证
4. 登出页面为/logout
5. 其他链接都需要进行验证

声明1个UserController,代码如下:

@Controller
public class UserController {

    @RequestMapping("/")
    public String index() {
        return "index";
    }

    @RequestMapping("/hello")
    public String hello() {
        return "hello";
    }

    @RequestMapping(value = "/login", method = RequestMethod.GET)
    public String login() {
        return "login";
    }

    @RequestMapping("/error-test")
    public String error() {
        return "1";
    }
} 

在src/main/resources/templates目录下创建如下几个页面:

hello.html,代码如下:

<!DOCTYPE html>
<html xmlns="http://www.w3.org/1999/xhtml" xmlns:th="http://www.thymeleaf.org"
      xmlns:sec="http://www.thymeleaf.org/thymeleaf-extras-springsecurity3">
<head>
    <title>Hello World!</title>
</head>
<body>
<h1 th:inline="text">Hello [[${#httpServletRequest.remoteUser}]]!</h1>
<form th:action="@{/logout}" method="post">
    <input type="submit" value="注销"/>
</form>
</body>
</html>

index.html,代码如下:

<!DOCTYPE html>
<html xmlns="http://www.w3.org/1999/xhtml" xmlns:th="http://www.thymeleaf.org"
      xmlns:sec="http://www.thymeleaf.org/thymeleaf-extras-springsecurity3">
<head>
    <title>Spring Security入门</title>
</head>
<body>
<h1>欢迎使用Spring Security!</h1>
<p>点击 <a th:href="@{/hello}">这里</a> 打个招呼吧</p>
</body>
</html>

login.html,代码如下:

<!DOCTYPE html>
<html xmlns="http://www.w3.org/1999/xhtml"
      xmlns:th="http://www.thymeleaf.org"
      xmlns:sec="http://www.thymeleaf.org/thymeleaf-extras-springsecurity3">
    <head>
        <title>Spring Security Example </title>
    </head>
    <body>
        <div th:if="${param.error}">
            用户名或密码错
        </div>
        <div th:if="${param.logout}">
            您已注销成功
        </div>
        <form th:action="@{/login}" method="post">
            <div><label> 用户名 : <input type="text" name="username"/> </label></div>
            <div><label> 密  码 : <input type="password" name="password"/> </label></div>
            <div><input type="submit" value="登录"/></div>
        </form>
    </body>
</html>

测试

启动应用后我们访问如下链接: http://127.0.0.1:8080/,返回的是如下页面:

点击index.html 中的超链接后,由于需要进行验证,返回到login页面,如图:

此时我们输入错误的用户名,密码,返回的页面如下:

此时我们输入user,password 后,返回的页面如下:

点击注销后,页面如下:

此时我们访问 http://127.0.0.1:8080/error-test,由于没有登录,还是调回到登录页面.

访问 http://127.0.0.1:8080/auditevents,返回的结果如下:

{
events: [
    {
    timestamp: "2018-01-23T03:52:13+0000",
    principal: "anonymousUser",
    type: "AUTHORIZATION_FAILURE",
    data: {
    details: {
    remoteAddress: "127.0.0.1",
    sessionId: null
    },
    type: "org.springframework.security.access.AccessDeniedException",
    message: "Access is denied"
    }
},
    {
    timestamp: "2018-01-23T03:54:21+0000",
    principal: "aaa",
    type: "AUTHENTICATION_FAILURE",
    data: {
    details: {
    remoteAddress: "127.0.0.1",
    sessionId: "DFDB023AEEF41BBD8079EC32402CBFD8"
    },
    type: "org.springframework.security.authentication.BadCredentialsException",
    message: "Bad credentials"
    }
    },
    {
    timestamp: "2018-01-23T03:55:50+0000",
    principal: "user",
    type: "AUTHENTICATION_SUCCESS",
    data: {
    details: {
    remoteAddress: "127.0.0.1",
    sessionId: "DFDB023AEEF41BBD8079EC32402CBFD8"
    }
    }
    },
    {
    timestamp: "2018-01-23T03:58:38+0000",
    principal: "anonymousUser",
    type: "AUTHORIZATION_FAILURE",
    data: {
    details: {
    remoteAddress: "127.0.0.1",
    sessionId: "6E6E614D638B6F5EE5B7E8CF516E2534"
    },
    type: "org.springframework.security.access.AccessDeniedException",
    message: "Access is denied"
    }
    },
    {
    timestamp: "2018-01-23T04:00:01+0000",
    principal: "anonymousUser",
    type: "AUTHORIZATION_FAILURE",
    data: {
    details: {
    remoteAddress: "127.0.0.1",
    sessionId: "6E6E614D638B6F5EE5B7E8CF516E2534"
    },
    type: "org.springframework.security.access.AccessDeniedException",
    message: "Access is denied"
    }
    },
    {
    timestamp: "2018-01-23T04:00:12+0000",
    principal: "user",
    type: "AUTHENTICATION_SUCCESS",
    data: {
    details: {
    remoteAddress: "127.0.0.1",
    sessionId: "6E6E614D638B6F5EE5B7E8CF516E2534"
    }
    }
    }
]
}

解析

1. 当我们访问 http://127.0.0.1:8080/hello.html 时,由于需要验证,因此会发送AuthorizationFailureEvent事件,此时会交由AuthorizationAuditListener处理,调用onAuthorizationFailureEvent方法.发送AuditEvent事件
2. AuditListener 监听该事件,最终执行onAuditEvent方法,将AuditEvent存入到InMemoryAuditEventRepository中.
3. 此时在login.html中,我们输入错误的用户名,密码,此时会发送AuthenticationFailureBadCredentialsEvent事件,交由AuthenticationAuditListener处理,最终执行onAuthenticationFailureEvent方法,发送AuditEvent事件, 最终还是在AuditListener中将事件存到 InMemoryAuditEventRepository中
4. 此时我们输入正确的用户名密码后,会发送AuthenticationSuccessEvent事件,交由AuthenticationAuditListener事件处理,最终执行onAuthenticationSuccessEvent方法,发送AuditEvent事件,最终还是在AuditListener中将事件存到InMemoryAuditEventRepository中
5. 之后产生了SessionFixationProtectionEvent事件,AuthenticationAuditListener不进行处理
6. 产生InteractiveAuthenticationSuccessEvent,AuthenticationAuditListener不进行处理.
7. 此时跳转到hello.html ,我们点击注销后,没有产生任何的事件.
8. 登录成功后,我们访问/error-log,由于需要ROLE_TEST权限,而user 只有ROLE_USER 权限,因此会产生AuthorizationFailureEvent事件,因此会交由AuthorizationAuditListener处理,发送AuditEvent事件,最终还是在AuditListener中将事件存到InMemoryAuditEventRepository中

zhuan：https://blog.csdn.net/qq_26000415/article/details/79138270