from http://cat0425.popo.blog.163.com/blog/static/7959643920098177232182/
<?xml version="1.0" encoding="UTF-8"?>
<configuration>
<appender name="stdout"
class="ch.qos.logback.core.ConsoleAppender">
<layout class="ch.qos.logback.classic.PatternLayout">
<Pattern>
%d{HH:mm:ss} [%thread] %-5level %logger{80} - %msg%n
</Pattern>
</layout>
</appender>
<appender name="R"
class="ch.qos.logback.core.rolling.RollingFileAppender">
<File>../ptvslog/server.log</File>
<layout class="ch.qos.logback.classic.PatternLayout">
<Pattern>
%d{HH:mm:ss} [%thread] %-5level %logger{80} - %msg%n
</Pattern>
</layout>
<rollingPolicy
class="ch.qos.logback.core.rolling.FixedWindowRollingPolicy">
<maxIndex>2</maxIndex>
<FileNamePattern>../ptvslog/server.log.%i</FileNamePattern>
</rollingPolicy>
<triggeringPolicy
class="ch.qos.logback.core.rolling.SizeBasedTriggeringPolicy">
<MaxFileSize>50MB</MaxFileSize>
</triggeringPolicy>
</appender>
（1）第一种配置如下时，将会使日志文件往后累加，而不是每日只生成当日的日志文件
<appender name="logfile"
class="ch.qos.logback.core.rolling.RollingFileAppender">
<File>../ptvslog/access.log</File>
<rollingPolicy
class="ch.qos.logback.core.rolling.TimeBasedRollingPolicy">
<FileNamePattern>
../ptvslog/access.%d{yyyy-MM-dd}.log
</FileNamePattern>
<!-- keep 1 days worth of history -->
<MaxHistory>1</MaxHistory>
</rollingPolicy>
<layout class="ch.qos.logback.classic.PatternLayout">
<Pattern>
%d{yyyy-MM-dd HH:mm:ss} -%msg%n
</Pattern>
</layout>
</appender>
（2）第二种配置如下时，按天生成日志文件，每天的日志文件里只保存当天的日志信息
<appender name="logfile2"
class="ch.qos.logback.core.rolling.RollingFileAppender">
<Prudent>true</Prudent>
<rollingPolicy
class="ch.qos.logback.core.rolling.TimeBasedRollingPolicy">
<FileNamePattern>
../ptvslog/access.%d{yyyy-MM-dd}.log
</FileNamePattern>
<!-- keep 60 days worth of history -->
<MaxHistory>60</MaxHistory>
</rollingPolicy>
<layout class="ch.qos.logback.classic.PatternLayout">
<Pattern>
%d{yyyy-MM-dd HH:mm:ss} -%msg%n
</Pattern>
</layout>
</appender>
（2）第三种配置如下时，按天生成文件夹，每个文件夹里放当天的日志文件
<appender name="logDirfile"
class="ch.qos.logback.core.rolling.RollingFileAppender">
<Prudent>true</Prudent>
<rollingPolicy
class="ch.qos.logback.core.rolling.TimeBasedRollingPolicy">
<FileNamePattern>
../ptvslog/%d{yyyy-MM-dd}/access.%d{yyyy-MM-dd}.log
</FileNamePattern>
</rollingPolicy>
<layout class="ch.qos.logback.classic.PatternLayout">
<Pattern>
%d{yyyy-MM-dd HH:mm:ss} -%msg%n
</Pattern>
</layout>
</appender>
以下配置表示DataController类的INFO日志以logDirfile输出，additivity="false"表示只在
logDirfile输出，不在其他输出台输出，如果设置为true，表示要在其他地方也输出。
<logger name="com.apabi.ptvs.web.DataController"
additivity="false">
<level value="INFO" />
<appender-ref ref="logDirfile" />
</logger>
<root level="INFO">
<appender-ref ref="stdout" />
<appender-ref ref="R" />
</root>
</configuration>