1.spring boot日志概述html
spring boot使用Commons Logging做为内部的日志系统,而且给Java Util Logging,Log4J2以及Logback都提供了默认的配置。
若是使用了spring boot的Starters,那么默认会使用Logback用于记录日志。java
2.spring boot日志默认配置web
咱们启动一个空的spring-boot项目看一下控制台的日志spring
控制台的默认配置sql
logging.pattern.console=%clr(%d{${LOG_DATEFORMAT_PATTERN:-yyyy-MM-dd HH:mm:ss.SSS}}){faint} %clr(${LOG_LEVEL_PATTERN:-%5p}) %clr(${PID:- }){magenta} %clr(---){faint} %clr([%15.15t]){faint} %clr(%-40.40logger{39}){cyan} %clr(:){faint} %m%n${LOG_EXCEPTION_CONVERSION_WORD:-%wEx}
其中%clr为配置不一样的颜色输出,支持的颜色有如下几种:express
blue
cyan
faint
green
magenta
red
yellow
输出顺序分析:apache
一、日期和时间--精确到毫秒,并按照时间进行简单的排序,格式为:bootstrap
%clr(%d{${LOG_DATEFORMAT_PATTERN:-yyyy-MM-dd HH:mm:ss.SSS}}){faint}tomcat
二、日志级别--ERROR,WARN,INFO,DEBUG,TRACEapp
%clr(${LOG_LEVEL_PATTERN:-%5p})
三、进程ID号
%clr(${PID:- })
四、日志内容,用"---"分隔符分开
%clr(---){faint}
五、线程名字--括在方括号中
%clr([%15.15t]){faint}
六、日志的名字--一般对应的是类名
%clr(%-40.40logger{39}){cyan}
注意:Logback没有FATAL级别(映射到ERROR)
不一样日志级别对应的颜色以下
3.spring boot日志配置
能够经过application.properties或者application.yml查看全部配置
每一个配置后面都有说明,就不一一赘述了。
4.spring boot日志实现原理
点击配置属性,能够进入LoggingApplicationListener这个类,
`/**
它实现了GenericApplicationListener接口,它默认定义了日志组DEFAULT_GROUP_LOGGERS和日志级别LOG_LEVEL_LOGGERS
private static final Map<String, List<String>> DEFAULT_GROUP_LOGGERS; static { MultiValueMap<String, String> loggers = new LinkedMultiValueMap<>(); loggers.add("web", "org.springframework.core.codec"); loggers.add("web", "org.springframework.http"); loggers.add("web", "org.springframework.web"); loggers.add("web", "org.springframework.boot.actuate.endpoint.web"); loggers.add("web", "org.springframework.boot.web.servlet.ServletContextInitializerBeans"); loggers.add("sql", "org.springframework.jdbc.core"); loggers.add("sql", "org.hibernate.SQL"); DEFAULT_GROUP_LOGGERS = Collections.unmodifiableMap(loggers); } private static final Map<LogLevel, List<String>> LOG_LEVEL_LOGGERS; static { MultiValueMap<LogLevel, String> loggers = new LinkedMultiValueMap<>(); loggers.add(LogLevel.DEBUG, "sql"); loggers.add(LogLevel.DEBUG, "web"); loggers.add(LogLevel.DEBUG, "org.springframework.boot"); loggers.add(LogLevel.TRACE, "org.springframework"); loggers.add(LogLevel.TRACE, "org.apache.tomcat"); loggers.add(LogLevel.TRACE, "org.apache.catalina"); loggers.add(LogLevel.TRACE, "org.eclipse.jetty"); loggers.add(LogLevel.TRACE, "org.hibernate.tool.hbm2ddl"); LOG_LEVEL_LOGGERS = Collections.unmodifiableMap(loggers); }
你也能够自定义logging.level和logging.group,它们都是map结构。LoggingApplicationListener重写了onApplicationEvent方法,实现日志的打印
@Override public void onApplicationEvent(ApplicationEvent event) { if (event instanceof ApplicationStartingEvent) { onApplicationStartingEvent((ApplicationStartingEvent) event); //1 } else if (event instanceof ApplicationEnvironmentPreparedEvent) { onApplicationEnvironmentPreparedEvent( (ApplicationEnvironmentPreparedEvent) event); //2 } else if (event instanceof ApplicationPreparedEvent) { onApplicationPreparedEvent((ApplicationPreparedEvent) event); //3 } else if (event instanceof ContextClosedEvent && ((ContextClosedEvent) event) .getApplicationContext().getParent() == null) { onContextClosedEvent(); //4 } else if (event instanceof ApplicationFailedEvent) { onApplicationFailedEvent(); //5 } }
第一步:根据classloader里加载的依赖决定使用哪一个日志系统?
主要实现有JavaLoggingSystem,Log4J2LoggingSystem,LogbackLoggingSystem
private void onApplicationStartingEvent(ApplicationStartingEvent event) { this.loggingSystem = LoggingSystem .get(event.getSpringApplication().getClassLoader()); this.loggingSystem.beforeInitialize(); }
第二步:经过classpath,enviroment等获取参数初始化日志系统
/** * Initialize the logging system according to preferences expressed through the * {@link Environment} and the classpath. * @param environment the environment * @param classLoader the classloader */ protected void initialize(ConfigurableEnvironment environment, ClassLoader classLoader) { new LoggingSystemProperties(environment).apply(); LogFile logFile = LogFile.get(environment); if (logFile != null) { logFile.applyToSystemProperties(); } initializeEarlyLoggingLevel(environment); initializeSystem(environment, this.loggingSystem, logFile); initializeFinalLoggingLevels(environment, this.loggingSystem); registerShutdownHookIfNecessary(environment, this.loggingSystem); }
第三步:注册springBootLoggingSystem
private void onApplicationPreparedEvent(ApplicationPreparedEvent event) { ConfigurableListableBeanFactory beanFactory = event.getApplicationContext() .getBeanFactory(); if (!beanFactory.containsBean(LOGGING_SYSTEM_BEAN_NAME)) { beanFactory.registerSingleton(LOGGING_SYSTEM_BEAN_NAME, this.loggingSystem); } }
第四步和第五步:日志系统清洗
private void onContextClosedEvent() { if (this.loggingSystem != null) { this.loggingSystem.cleanUp(); } } private void onApplicationFailedEvent() { if (this.loggingSystem != null) { this.loggingSystem.cleanUp(); } }
5.自定义配置文件
日志系统 自定义配置文件
Logback
logback-spring.xml, logback-spring.groovy, logback.xml, or logback.groovy
Log4j2
log4j2-spring.xml or log4j2.xml
JDK (Java Util Logging)
logging.properties
6.总结
spring boot日志系统封装了logback,log4j2和java log,默认状况下使用java log,一旦使用各类starts,则默认使用Log4J2,也能够经过classpath来改变,pom.xml指定
<dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter</artifactId> <exclusions> <exclusion> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-logging</artifactId> </exclusion> </exclusions> </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-log4j</artifactId> </dependency>
参考资料