You can set the log file location and name as a parameter element in the log4J xml

<param name="File" value="C:\\logs\\application\\ApplicationLog.log" />

Example file below:

<log4j:configuration>
    <appender name="STDOUT" class="org.apache.log4j.RollingFileAppender">
        <param name="File"     value="C:\\logs\\application\\ApplicationLog.${user.name}.log" />
        <param name="MaxFileSize" value="5000KB" />
        <param name="MaxBackupIndex" value="10" />
        <layout class="org.apache.log4j.PatternLayout">
            <param name="ConversionPattern"
        value="[%d{yyyy-MMM-dd HH:mm:ss}] [%t] %-5p %c{1}: %m %n" />
        </layout>
        <filter class="org.apache.log4j.varia.LevelRangeFilter">
            <param name="LevelMin" value="DEBUG"/>
            <param name="LevelMax" value="FATAL"/>
        </filter>
    </appender>

    <root>
        <level value="all" />
        <appender-ref ref="STDOUT"/>
    </root>
</log4j:configuration>