##LoggingApplicationListener监听

@Overridepublic void onApplicationEvent(ApplicationEvent event) {if (event instanceof ApplicationStartingEvent) {onApplicationStartingEvent((ApplicationStartingEvent) event);}else if (event instanceof ApplicationEnvironmentPreparedEvent) {onApplicationEnvironmentPreparedEvent((ApplicationEnvironmentPreparedEvent) event);}else if (event instanceof ApplicationPreparedEvent) {onApplicationPreparedEvent((ApplicationPreparedEvent) event);}else if (event instanceof ContextClosedEvent&& ((ContextClosedEvent) event).getApplicationContext().getParent() == null) {onContextClosedEvent();}else if (event instanceof ApplicationFailedEvent) {onApplicationFailedEvent();}}

##初始化

protected void initialize(ConfigurableEnvironment environment, ClassLoader classLoader) {new LoggingSystemProperties(environment).apply();this.logFile = LogFile.get(environment);if (this.logFile != null) {this.logFile.applyToSystemProperties();}this.loggerGroups = new LoggerGroups(DEFAULT_GROUP_LOGGERS);initializeEarlyLoggingLevel(environment);initializeSystem(environment, this.loggingSystem, this.logFile);initializeFinalLoggingLevels(environment, this.loggingSystem);registerShutdownHookIfNecessary(environment, this.loggingSystem);}

##Spring boot 集成logback日志框架 

org.springframework.boot.logging.logback.LogbackLoggingSystem

this.loggingSystem = LoggingSystem.get(event.getSpringApplication().getClassLoader());

##String logConfig = environment.getProperty(CONFIG_PROPERTY);//取出配置文件log xml配置

##解析xml文档

##实例化xml配置节点日志对象ch.qos.logback.core.rolling.RollingFileAppender

##日志对象存到这个InterpretationContext上下文

##添加到appenderList集合容器，循环调用输出日志到文件或控制台