springboot2配置日志

Spring Boot内部采用的是Commons Logging进行日志记录，但在底层为Java Util Logging、Log4J2、Logback等日志框架提供了默认配置 。Java 虽然有很多可用的日志框架，但SpringBoot默认使用的Logback的框架。

springboot默认的日志级别是INFO，，配置如下

logging:
  level: debug

注意：这样配置启动会报如下错误

org.springframework.boot.context.properties.bind.BindException: Failed to bind properties under 'logging.level' to java.util.Map<java.lang.String, org.springframework.boot.logging.LogLevel>

因为logging.level的值需要Map<String,String>类型，正确的配置如下：

logging:
  level: 
    root: debug

假设你要到某个目录下设置日志级别，比如目录为com.demo 则配置如下

logging:
  level: 
    com.demo: debug

除了使用配置文件配置，还可以使用logback.xml的配置，具体如下：

<?xml version="1.0" encoding="UTF-8"?>
<configuration debug="false" scan="true" scanPeriod="1000 seconds">
	<property name="log.dir" value="./logs/" />
	<property name="log.filename" value="springcloud" />

	<!-- Output to Console -->
	<appender name="Console" class="ch.qos.logback.core.ConsoleAppender">
		<encoder>
			<pattern>[%date{yyyy-MM-dd HH:mm:ss.SSS}][%thread][%-5level][%logger:%line]--%mdc{client} %msg%n</pattern>
			<charset>UTF-8</charset>
		</encoder>
	</appender>

	<!-- 文件输出日志 (文件大小策略进行文件输出，超过指定大小对文件备份) -->
	<appender name="FILE"
			  class="ch.qos.logback.core.rolling.RollingFileAppender">
		<file>${log.dir}${log.filename}.log</file>
		<rollingPolicy class="ch.qos.logback.core.rolling.TimeBasedRollingPolicy">
			<fileNamePattern>${log.dir}${log.filename}.%d{yyyy-MM-dd}.%i.log
			</fileNamePattern>
			<maxHistory>10</maxHistory>
			<cleanHistoryOnStart>true</cleanHistoryOnStart>
			<timeBasedFileNamingAndTriggeringPolicy
					class="ch.qos.logback.core.rolling.SizeAndTimeBasedFNATP">
				<maxFileSize>500MB</maxFileSize>
			</timeBasedFileNamingAndTriggeringPolicy>
		</rollingPolicy>
		<encoder>
			<Pattern>[%date{yyyy-MM-dd HH:mm:ss.SSS}][%thread][%-5level][%logger:%line]--%mdc{client} %msg%n</Pattern>
		</encoder>
	</appender>

	<!-- 文件输出日志 (文件大小策略进行文件输出，超过指定大小对文件备份) -->
	<appender name="ERRORFILE"
			  class="ch.qos.logback.core.rolling.RollingFileAppender">
		<file>${log.dir}${log.filename}-error.log</file>
		<rollingPolicy class="ch.qos.logback.core.rolling.TimeBasedRollingPolicy">
			<fileNamePattern>${log.dir}${log.filename}-error.%d{yyyy-MM-dd}.%i.log
			</fileNamePattern>
			<maxHistory>10</maxHistory>
			<cleanHistoryOnStart>true</cleanHistoryOnStart>
			<timeBasedFileNamingAndTriggeringPolicy
					class="ch.qos.logback.core.rolling.SizeAndTimeBasedFNATP">
				<maxFileSize>500MB</maxFileSize>
			</timeBasedFileNamingAndTriggeringPolicy>
		</rollingPolicy>
		<encoder>
			<Pattern>[%date{yyyy-MM-dd HH:mm:ss.SSS}][%thread][%-5level][%logger:%line]--%mdc{client} %msg%n</Pattern>
		</encoder>
		<filter class="ch.qos.logback.classic.filter.LevelFilter">
			<level>ERROR</level>
			<onMatch>ACCEPT</onMatch>
			<onMismatch>DENY</onMismatch>
		</filter>
	</appender>


	<!-- 打印级别，大小写无关：TRACE, DEBUG, INFO, WARN, ERROR, ALL 和  OFF 默认是DEBUG -->
	<root level="debug">
		<appender-ref ref="Console" />
		<appender-ref ref="FILE" />
		<appender-ref ref="ERRORFILE" />
		<!--<appender-ref ref="LOGSTASH" />-->
	</root>
	<logger name="com.channelsoft" level="DEBUG" />
	<logger name="org.springframework" level="info" />
	<logger name="org.apache.tomcat" level="info" />
	<logger name="org.apache.shiro" level="trace" />
	<logger name="sun" level="info" />
	<logger name="javax" level="info" />
	<!--<logger name="org.springframework.web.servlet.DispatcherServlet" level="DEBUG" />-->
</configuration>

以上的配置项，在此就不赘述了，基本上都是通用配置。