SpringCloud+Logback配置实例

Dear 丶 2021-09-02 07:07 696阅读 0赞

boot+logback+nacos方案：[https://blog.csdn.net/z69183787/article/details/108948325][https_blog.csdn.net_z69183787_article_details_108948325]

正常情况下使用 springboot + logback + nacos 进行日志级别动态变更是没有问题的，但当和springcloud一起使用时，会发生 logger级别重置的情况，即设置完某个logger的独立级别后，整个logger上下文会重新刷新，并且重置logger 为 Root设置的 level 级别。经过一番源码的探查，目前还未找到问题的原因和解决方案；但与此同时，却发现了另一种实现这个效果的方案：

使用 logging.level 属性进行配置，在nacos变更后，应用会自动生效

nacos配置：

logging:
      level:
       com.xxx.xxxx.demo.controller: ERROR
       com.zzz.zzzz.demo.controller: INFO

关键源码：

Nacos接收到配置变化后进入 NacosContextRefresher 类，核心方法如下：

可以看到 配置修改后，触发了listener，在listener中发布了一个 RefreshEvent

private void registerNacosListener(final String groupKey, final String dataKey) {
    		String key = NacosPropertySourceRepository.getMapKey(dataKey, groupKey);
    		Listener listener = listenerMap.computeIfAbsent(key,
    				lst -> new AbstractSharedListener() {
    					@Override
    					public void innerReceive(String dataId, String group,
    							String configInfo) {
    						refreshCountIncrement();
    						nacosRefreshHistory.addRefreshRecord(dataId, group, configInfo);
    						// todo feature: support single refresh for listening
    						applicationContext.publishEvent(
    								new RefreshEvent(this, null, "Refresh Nacos config"));
    						if (log.isDebugEnabled()) {
    							log.debug(String.format(
    									"Refresh Nacos config group=%s,dataId=%s,configInfo=%s",
    									group, dataId, configInfo));
    						}
    					}
    				});
    		try {
    			configService.addListener(dataKey, groupKey, listener);
    		}
    		catch (NacosException e) {
    			log.warn(String.format(
    					"register fail for nacos listener ,dataId=[%s],group=[%s]", dataKey,
    					groupKey), e);
    		}
    	}

RefreshEvent

public RefreshEvent(Object source, Object event, String eventDesc) {
    		super(source);
    		this.event = event;
    		this.eventDesc = eventDesc;
    	}

进入 AbstractApplicationContext中的 event广播 multicastEvent

@Override
    	public void multicastEvent(final ApplicationEvent event, @Nullable ResolvableType eventType) {
    		ResolvableType type = (eventType != null ? eventType : resolveDefaultEventType(event));
    		Executor executor = getTaskExecutor();
    		for (ApplicationListener<?> listener : getApplicationListeners(event, type)) {
    			if (executor != null) {
    				executor.execute(() -> invokeListener(listener, event));
    			}
    			else {
    				invokeListener(listener, event);
    			}
    		}
    	}

进入SimpleApplicationEventMulticaster 的 invokeListener方法，进而触发所有满足 eventType 的 listener进行 onApplicationEvent 回调

protected void invokeListener(ApplicationListener<?> listener, ApplicationEvent event) {
    		ErrorHandler errorHandler = getErrorHandler();
    		if (errorHandler != null) {
    			try {
    				doInvokeListener(listener, event);
    			}
    			catch (Throwable err) {
    				errorHandler.handleError(err);
    			}
    		}
    		else {
    			doInvokeListener(listener, event);
    		}
    	}
    
    
    
    	private void doInvokeListener(ApplicationListener listener, ApplicationEvent event) {
    		try {
    			listener.onApplicationEvent(event);
    		}

满足 RefreshEvent 的 Listener 是  RefreshEventListener

@Override
    	public boolean supportsEventType(Class<? extends ApplicationEvent> eventType) {
    		return ApplicationReadyEvent.class.isAssignableFrom(eventType)
    				|| RefreshEvent.class.isAssignableFrom(eventType);
    	}
    
    	@Override
    	public void onApplicationEvent(ApplicationEvent event) {
    		if (event instanceof ApplicationReadyEvent) {
    			handle((ApplicationReadyEvent) event);
    		}
    		else if (event instanceof RefreshEvent) {
    			handle((RefreshEvent) event);
    		}
    	}
    
    	public void handle(ApplicationReadyEvent event) {
    		this.ready.compareAndSet(false, true);
    	}
    
    	public void handle(RefreshEvent event) {
    		if (this.ready.get()) { // don't handle events before app is ready
    			log.debug("Event received " + event.getEventDesc());
    			Set<String> keys = this.refresh.refresh();
    			log.info("Refresh keys changed: " + keys);
    		}
    	}

Set<String> keys = this.refresh.refresh(); 方法中 调用了 ContextRefresher 中的方法，可以看到发布了一个 EnvironmentChangeEvent 事件

public synchronized Set<String> refresh() {
    		Set<String> keys = refreshEnvironment();
    		this.scope.refreshAll();
    		return keys;
    	}
    
    	public synchronized Set<String> refreshEnvironment() {
    		Map<String, Object> before = extract(
    				this.context.getEnvironment().getPropertySources());
    		addConfigFilesToEnvironment();
    		Set<String> keys = changes(before,
    				extract(this.context.getEnvironment().getPropertySources())).keySet();
    		this.context.publishEvent(new EnvironmentChangeEvent(this.context, keys));
    		return keys;
    	}

监听 EnvironmentChangeEvent 事件的监听器是 LoggingRebinder，可以明显的看到

1、获取 yaml配置文件中的 logging.level 中的配置，即上文中 nacos 的配置项（Map<String,String> 结构）

2、然后分别进行设置生效

@Override
    	public void onApplicationEvent(EnvironmentChangeEvent event) {
    		if (this.environment == null) {
    			return;
    		}
    		LoggingSystem system = LoggingSystem.get(LoggingSystem.class.getClassLoader());
    		setLogLevels(system, this.environment);
    	}
    
    	protected void setLogLevels(LoggingSystem system, Environment environment) {
    		Map<String, String> levels = Binder.get(environment)
    				.bind("logging.level", STRING_STRING_MAP)
    				.orElseGet(Collections::emptyMap);
    		for (Entry<String, String> entry : levels.entrySet()) {
    			setLogLevel(system, environment, entry.getKey(), entry.getValue().toString());
    		}
    	}
    
    	private void setLogLevel(LoggingSystem system, Environment environment, String name,
    			String level) {
    		try {
    			if (name.equalsIgnoreCase("root")) {
    				name = null;
    			}
    			level = environment.resolvePlaceholders(level);
    			system.setLogLevel(name, resolveLogLevel(level));
    		}
    		catch (RuntimeException ex) {
    			this.logger.error("Cannot set level: " + level + " for '" + name + "'");
    		}
    	}

最终经过调试，可以完美满足 动态变更 日志级别的需求，但是为何方案一会 重置 日志级别还是没有解决，未完待续。。。

附上工具类，输出所有日志及package的 日志级别

/**
      * 查询所有配置的日志级别
     */
     @GetMapping("/loggerList")
     public List<LogInfoVO> queryLoggerList(){
           LoggerContext loggerContext = (LoggerContext) LoggerFactory.getILoggerFactory();
           return loggerContext.getLoggerList().stream()
                   .map(log -> new LogInfoVO(log.getName(), log.getLevel()!=null?log.getLevel().levelStr:"null",log.getEffectiveLevel().levelStr))
                   .collect(Collectors.toList());
     }

[https_blog.csdn.net_z69183787_article_details_108948325]: https://blog.csdn.net/z69183787/article/details/108948325