解决 maxfilesize property is manatory 的问题

问题配置如下图所示：

<?xml version="1.0" encoding="UTF-8"?>
<configuration>
    <appender name="File" class="ch.qos.logback.core.rolling.RollingFileAppender">
        <rollingPolicy class="ch.qos.logback.core.rolling.SizeAndTimeBasedRollingPolicy">
            <fileNamePattern>/home/appadmin/logs/test.%i.log.zip</fileNamePattern>
            <maxHistory>365</maxHistory>
            <totalSizeCap>10GB</totalSizeCap>
            <timeBasedFileNamingAndTriggeringPolicy class="ch.qos.logback.core.rolling.SizeAndTimeBasedFNATP">
                <maxFileSize>100 MB</maxFileSize>
            </timeBasedFileNamingAndTriggeringPolicy>
        </rollingPolicy>
    </appender>
</configuration>

运行时报 maxfilesize property is manatory 的错误

先说一下解决办法：
解决方法1：将SizeAndTimeBasedRollingPolicy 改为TimeBasedRollingPolicy

<?xml version="1.0" encoding="UTF-8"?>
<configuration>
    <appender name="File" class="ch.qos.logback.core.rolling.RollingFileAppender">
        <rollingPolicy class="ch.qos.logback.core.rolling.TimeBasedRollingPolicy">
            <fileNamePattern>/home/appadmin/logs/test.%i.log.zip</fileNamePattern>
            <maxHistory>365</maxHistory>
            <totalSizeCap>10GB</totalSizeCap>
            <timeBasedFileNamingAndTriggeringPolicy class="ch.qos.logback.core.rolling.SizeAndTimeBasedFNATP">
                <maxFileSize>100 MB</maxFileSize>
            </timeBasedFileNamingAndTriggeringPolicy>
        </rollingPolicy>
    </appender>
</configuration>

解决方法2：将maxFileSize放到timeBasedFileNamingAndTriggeringPolicy 外面

<?xml version="1.0" encoding="UTF-8"?>
<configuration>
    <appender name="File" class="ch.qos.logback.core.rolling.RollingFileAppender">
        <rollingPolicy class="ch.qos.logback.core.rolling.SizeAndTimeBasedRollingPolicy ">
            <fileNamePattern>/home/appadmin/logs/test.%i.log.zip</fileNamePattern>
            <maxHistory>365</maxHistory>
            <totalSizeCap>10GB</totalSizeCap>
            <maxFileSize>100 MB</maxFileSize>
            <timeBasedFileNamingAndTriggeringPolicy class="ch.qos.logback.core.rolling.SizeAndTimeBasedFNATP">
            </timeBasedFileNamingAndTriggeringPolicy>
        </rollingPolicy>
    </appender>
</configuration>

两种方法都可以解决问题

分析原因：
先来看看SizeAndTimeBasedRollingPolicy

再来看看SizeAndTimeBasedFNATP

两个类里面都有maxFileSize的属性，而当配置文件存在这两个类的时候，maxFileSize会以SizeAndTimeBasedRollingPolicy 的配置为准

因为运行时先走的SizeAndTimeBasedRollingPolicy ，虽然SizeAndTimeBasedFNATP里配置了maxFileSize，但是SizeAndTimeBasedRollingPolicy 里判断的是自己的maxFileSize,再赋值给SizeAndTimeBasedFNATP

所以导致SizeAndTimeBasedFNATP明明配置了maxFileSize,但是运行的时候maxFileSize还是为null

而TimeBasedRollingPolicy中则不包含maxFileSize的属性，所以配置不会出错

以上均为个人理解，如有问题欢迎在评论补充