logback.xml示例文件：
<?xml version="1.0" encoding="UTF-8"?>
<configuration scan="true">
<property name="log.root.level" value="DEBUG" /> <!-- 日志级别 -->
<property name="log.other.level" value="DEBUG" /> <!-- 其他日志级别 -->
<property name="log.moduleName" value="elasticSearch5.2" /> <!-- 模块名称， 影响日志配置名，日志文件名 -->
<!--日志文件的保存路径,首先查找系统属性-Dlog.dir,如果存在就使用其；否则，在当前目录下创建名为logs目录做日志存放的目录 -->
<property name="log.base" value="${log.dir:-logs}/${log.moduleName}" />
<property name="log.max.size" value="100MB" /> <!-- 日志文件大小,超过这个大小将被压缩 -->
<!--控制台输出 -->
<appender name="stdout" class="ch.qos.logback.core.ConsoleAppender">
<encoder class="ch.qos.logback.classic.encoder.PatternLayoutEncoder">
<Pattern>%date{yyyy-MM-dd HH:mm:ss.SSS} %-5level[%thread]%logger{56}.%method:%L -%msg%n</Pattern>
</encoder>
</appender>
<!-- 用来保存输出所有级别的日志 -->
<appender name="file.all" class="ch.qos.logback.core.rolling.RollingFileAppender">
<File>${log.base}/${log.moduleName}.log</File><!-- 设置日志不超过${log.max.size}时的保存路径，注意如果
是web项目会保存到Tomcat的bin目录 下 -->
<!-- 滚动记录文件，先将日志记录到指定文件，当符合某个条件时，将日志记录到其他文件。 -->
<rollingPolicy class="ch.qos.logback.core.rolling.TimeBasedRollingPolicy">
<FileNamePattern>${log.base}/archive/${log.moduleName}_all_%d{yyyy-MM-dd}.%i.log.zip
</FileNamePattern>
<!-- 文件输出日志 (文件大小策略进行文件输出，超过指定大小对文件备份) -->
<timeBasedFileNamingAndTriggeringPolicy
class="ch.qos.logback.core.rolling.SizeAndTimeBasedFNATP">
<maxFileSize>${log.max.size}</maxFileSize>
</timeBasedFileNamingAndTriggeringPolicy>
</rollingPolicy>
<!-- 日志输出的文件的格式 -->
<layout class="ch.qos.logback.classic.PatternLayout">
<pattern>%date{yyyy-MM-dd HH:mm:ss.SSS} %-5level[%thread]%logger{56}.%method:%L -%msg%n</pattern>
</layout>
</appender>
<!-- 这也是用来保存输出所有级别的日志 -->
<appender name="file.all.other" class="ch.qos.logback.core.rolling.RollingFileAppender">
<File>${log.base}/${log.moduleName}_other.log</File>
<rollingPolicy class="ch.qos.logback.core.rolling.TimeBasedRollingPolicy">
<FileNamePattern>${log.base}/archive/${log.moduleName}_other_%d{yyyy-MM-dd}.%i.log.zip
</FileNamePattern>
<timeBasedFileNamingAndTriggeringPolicy
class="ch.qos.logback.core.rolling.SizeAndTimeBasedFNATP">
<maxFileSize>${log.max.size}</maxFileSize>
</timeBasedFileNamingAndTriggeringPolicy>
</rollingPolicy>
<layout class="ch.qos.logback.classic.PatternLayout">
<pattern>%date{yyyy-MM-dd HH:mm:ss.SSS} %-5level [%thread] %logger{56}.%method:%L -%msg%n</pattern>
</layout>
</appender>
<!-- 只用保存输出error级别的日志 -->
<appender name="file.error"
class="ch.qos.logback.core.rolling.RollingFileAppender">
<File>${log.base}/${log.moduleName}_err.log</File>
<rollingPolicy class="ch.qos.logback.core.rolling.TimeBasedRollingPolicy">
<FileNamePattern>${log.base}/archive/${log.moduleName}_err_%d{yyyy-MM-dd}.%i.log.zip
</FileNamePattern>
<timeBasedFileNamingAndTriggeringPolicy
class="ch.qos.logback.core.rolling.SizeAndTimeBasedFNATP">
<maxFileSize>${log.max.size}</maxFileSize>
</timeBasedFileNamingAndTriggeringPolicy>
</rollingPolicy>
<layout class="ch.qos.logback.classic.PatternLayout">
<pattern>%date{yyyy-MM-dd HH:mm:ss.SSS} %-5level [%thread] %logger{56}.%method:%L - %msg%n</pattern>
</layout>
<!-- 下面为配置只输出error级别的日志 -->
<filter class="ch.qos.logback.classic.filter.LevelFilter">
<level>ERROR</level>
<onMatch>ACCEPT</onMatch>
<onMismatch>DENY</onMismatch>
</filter>
</appender>
<!-- 不丢失日志.默认的,如果队列的80%已满,则会丢弃TRACT、DEBUG、INFO级别的日志 -->
<!-- 更改默认的队列的深度,该值会影响性能.默认值为256 -->
<!-- 添加附加的appender,最多只能添加一个 -->
<appender name="file.async" class="ch.qos.logback.classic.AsyncAppender">
<discardingThreshold>0</discardingThreshold>
<queueSize>256</queueSize>
<includeCallerData>true</includeCallerData>
<appender-ref ref="file.all" />
</appender>
<!-- 使用异步来记录其他信息-->
<appender name="file.async.other" class="ch.qos.logback.classic.AsyncAppender">
<discardingThreshold>0</discardingThreshold>
<queueSize>256</queueSize>
<includeCallerData>true</includeCallerData>
<appender-ref ref="file.all.other" />
</appender>
<!-- 为某个包下的所有类的指定Appender 这里也可以指定类名称例如：com.aa.bb.ClassName -->
<logger name="com.lin" additivity="false">
<level value="${log.root.level}" />
<appender-ref ref="stdout" />
<appender-ref ref="file.async" /><!-- 即com.lin包下级别为 ${log.root.level}的才会使用file.async来打印 -->
<appender-ref ref="file.error" />
</logger>
<!-- root将级别为${log.root.level}及大于${log.root.level}的日志信息交给已经配置好的名为“Console”的appender处理，“Console”appender将信息打印到Console,其它同理 -->
<root level="${log.root.level}">
<appender-ref ref="stdout" /> <!-- 标识这个appender将会添加到这个logger -->
<appender-ref ref="file.async.other" />
<appender-ref ref="file.error" />
</root>
</configuration>properties也是可以的：
log4j.rootLogger=info, ServerDailyRollingFile, stdout
log4j.appender.ServerDailyRollingFile=org.apache.log4j.DailyRollingFileAppender
log4j.appender.ServerDailyRollingFile.DatePattern='.'yyyy-MM-dd
log4j.appender.ServerDailyRollingFile.File=logs/notify-subscription.log
log4j.appender.ServerDailyRollingFile.layout=org.apache.log4j.PatternLayout
log4j.appender.ServerDailyRollingFile.layout.ConversionPattern=%d - %m%n
log4j.appender.ServerDailyRollingFile.Append=true
log4j.appender.stdout=org.apache.log4j.ConsoleAppender
log4j.appender.stdout.layout=org.apache.log4j.PatternLayout
log4j.appender.stdout.layout.ConversionPattern=%d{yyyy-MM-dd HH\:mm\:ss} %p [%c] %m%n
