Different log4j layout for debug and error?

configuration, java, log4j, logging

Solution

Within your log4j.xml configuration, you can create two appenders, each using a LevelMatchFilter and each with a separate pattern output.

Problem

In log4j, is there a way to have logger.error("") and logger.debug("") include different output layouts? I'd like errors to include method names and line numbers, both of which slow down application performance. EDIT: After adding apache-log4j-extras, the following config file works. ``` <?xml version="1.0" encoding="UTF-8"?> <!DOCTYPE log4j:configuration SYSTEM "log4j.dtd" > <log4j:configuration xmlns:log4j="http://jakarta.apache.org/log4j/"> <appender name="WARNINGS" class="org.apache.log4j.DailyRollingFileAppender"> <param name="File" value="warnings.log"/> <param name="DatePattern" value="'.'yyyy-MM-dd"/> <layout class="org.apache.log4j.PatternLayout"> <param name="ConversionPattern" value="%d{yyyy-MMM-dd HH:mm:ss} %-5p %c - %m%n%n"/> </layout> <filter class="org.apache.log4j.filter.LevelRangeFilter"> <param name="LevelMin" value="DEBUG"/> <param name="LevelMax" value="WARN"/> </filter> </appender> <appender name="ERRORS" class="org.apache.log4j.DailyRollingFileAppender"> <param name="File" value="errors.log"/> <param name="DatePattern" value="'.'yyyy-MM-dd"/> <layout class="org.apache.log4j.PatternLayout"> <!-- %M for method name , %L for line number --> <param name="ConversionPattern" value="%d{yyyy-MMM-dd HH:mm:ss} %-5p %c %M %L - %m%n%n"/> </layout> <filter class="org.apache.log4j.filter.LevelRangeFilter"> <param name="LevelMin" value="ERROR"/> <param name="LevelMax" value="FATAL"/> </filter> </appender> <logger name="com.foo.bar"> <appender-ref ref="WARNINGS"/> <appender-ref ref="ERRORS"/> </logger> </log4j:configuration> ``` This code was used to test ``` // goes to errors.txt log.error("error"); //goes to warnings.txt log.warn("warn"); ```

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