How to change the log4j log file name dynamically

Question

I am sure that this question is answered multiple times. But somehow, it's not working for me.

My appender is something like this.

<appender name="myAppender" class="org.apache.log4j.DailyRollingFileAppender">
    <param name="Threshold" value="DEBUG"/>
    <param name="File" value="D:\\out\\MyApp_${output}.log"/>
    <param name="DatePattern" value="'.'yyyy-MM-dd"/>
    <param name="Append" value="true"/>
    <layout class="org.apache.log4j.PatternLayout">
        <param name="ConversionPattern" value="%d{DATE} %5p %C{1}:%L - %m%n"/>
    </layout>
</appender>

I am setting the system property before creating the logger.

System.setProperty("output", "abc");

Then, I am creating the logger like this.

logger = Logger.getLogger("myAppender");

But the output file is generated only like this.

MyApp_.log

Am I missing something? Thanks in advance.

score 0 · Answer 1 · edited May 23 '17 at 12:25

0

Did you try -Doutput=abc during the startup?

Here is another thread with similar problem that may help you.

How to give environmental variable path for file appender in configuration file in log4j

edited May 23 '17 at 12:25

Community

1
1

answered Dec 11 '14 at 18:03

Jags Krishnamurthy

112
2

I can't use this option since I don't know the value during startup. – Shan Dec 11 '14 at 19:08
It looks like we have to initialize the log4j file after setting the system property. – Shan Dec 11 '14 at 19:10
System.setProperty("output", "abc"); followed by DOMConfigurator.configure("MyLog4j.xml") – Shan Dec 11 '14 at 19:11

How to change the log4j log file name dynamically

1 Answers1