如何将 logback 文件路径概括为 windows/linux 操作系统？

Question

I have a java app. My development enviourment is a Windows OS and my production OS is linux. The app needs to read/write some files in the OS, among these - log files (I'm using logback lib). In my windows dev enviourment, I configured the log path to be at absolute position: C://logger/my-app.log

Following is the relevant logback.xml config file code:

<appender name="FILE" class="ch.qos.logback.core.rolling.RollingFileAppender">
    <file>C://logger/my-app.log</file>
    <rollingPolicy class="ch.qos.logback.core.rolling.TimeBasedRollingPolicy">
        <fileNamePattern>C://logger/my-app-%d{yyyy-MM-dd}.log</fileNamePattern>
        <maxHistory>30</maxHistory>
    </rollingPolicy>
    <encoder>
        <charset>UTF-8</charset>
        <pattern>%d{yyyy-MM-dd HH:mm:ss} [%thread] %-5level %logger{36} - %msg%n</pattern>
    </encoder>
</appender>

But, as mintioned, my prod enviourment is a linux OS. I want to create the file at absolute path also in the linux machine, with a single config xml file. I don't want the file to be created in the context of the deployed jar file but in some absolute path. How can it be done?

Answer 1

To make the web application portable and the log file should be generated irrespective of any OS. You have to use user.home environment variable property. I provide below the logback snippet which will work on both Windows and Linux.

<appender name="FILE" class="ch.qos.logback.core.rolling.RollingFileAppender">
    <file>${user.home}/logs/my-app.log</file>
    <rollingPolicy class="ch.qos.logback.core.rolling.TimeBasedRollingPolicy">
        <fileNamePattern>C://logger/my-app-%d{yyyy-MM-dd}.log</fileNamePattern>
        <maxHistory>30</maxHistory>
    </rollingPolicy>
    <encoder>
        <charset>UTF-8</charset>
        <pattern>%d{yyyy-MM-dd HH:mm:ss} [%thread] %-5level %logger{36} - %msg%n</pattern>
    </encoder>
</appender>