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Logging different levels using same object to different files

My simple question is : If I have two statements like logger.info() and logger.error() in Java (using log4j), I want the results of these two lines to be printed in two separate files. That is, logger.info(...) should print to a file say myLog.info and logger.error(...) should print to myLog.error file. I am using rolling file appender for this task. Also I want just one logger object to do the task. Someone might suggest two or more different loggers one for each file, but that's not the case.
I tried searching a solution for the problem. One of the links Creating multiple log files of different content with log4j says about "threshold" and I even tried to add threshold in my xml configuration file. But what it actually is doing that : info log is being printed in myLog.info file but error log gets printed in both the files. Can it be done through xml configuration file alone or a separate properties file is needed? If xml file is sufficient, then what needs to be done?
I am preferring xml file over properties file. If there is a working solution using only xml configuration file, that would be sufficient. Thanks in advance.

You could use filters to deny any messages except those of the level you want. Here is an example of how to do this:
First a class to test our efforts:
package test;
import org.apache.log4j.Logger;
public class Main {
private static final Logger logger = Logger.getLogger(Main.class);
public static void main(String[] args) {
logger.debug("here's some debug");
logger.info("here's some info");
logger.warn("here's some warn");
logger.error("here's some error");
logger.fatal("here's some fatal");
}
}
Next a log4j.xml config file to set up the appenders and loggers:
<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE log4j:configuration SYSTEM "log4j.dtd">
<log4j:configuration xmlns:log4j='http://jakarta.apache.org/log4j/'>
<appender name="consoleAppender" class="org.apache.log4j.ConsoleAppender">
<layout class="org.apache.log4j.PatternLayout">
<param name="ConversionPattern" value="%d %-5p [%c{1}] %m %n" />
</layout>
</appender>
<appender name="debugLog" class="org.apache.log4j.RollingFileAppender">
<param name="File" value="logs/debug.log" />
<param name="Append" value="true" />
<param name="MaxFileSize" value="5000KB" />
<param name="maxBackupIndex" value="5" />
<layout class="org.apache.log4j.PatternLayout">
<param name="ConversionPattern" value="%d{yyyy-MM-dd HH:mm:ss} [%t] %-5p - %m%n" />
</layout>
<filter class="org.apache.log4j.varia.LevelMatchFilter">
<param name="LevelToMatch" value="DEBUG" />
<param name="AcceptOnMatch" value="true" />
</filter>
<filter class="org.apache.log4j.varia.DenyAllFilter" />
</appender>
<appender name="infoLog" class="org.apache.log4j.RollingFileAppender">
<param name="File" value="logs/info.log" />
<param name="Append" value="true" />
<param name="MaxFileSize" value="5000KB" />
<param name="maxBackupIndex" value="5" />
<layout class="org.apache.log4j.PatternLayout">
<param name="ConversionPattern" value="%d{yyyy-MM-dd HH:mm:ss} [%t] %-5p - %m%n" />
</layout>
<filter class="org.apache.log4j.varia.LevelMatchFilter">
<param name="LevelToMatch" value="INFO" />
<param name="AcceptOnMatch" value="true" />
</filter>
<filter class="org.apache.log4j.varia.DenyAllFilter" />
</appender>
<logger name="test" additivity="false">
<level value="DEBUG" />
<appender-ref ref="consoleAppender" />
<appender-ref ref="debugLog" />
<appender-ref ref="infoLog" />
</logger>
</log4j:configuration>
This pattern will allow you to generate a separate log for each log level, just repeat the configuration that I have provided for either debug or info logging. Note that the console appender will accept all levels.
I was able to gain some insight from this post so I thought I should give credit.

Trouble with log4j configuration

I have been trying to change the logging from console to both console as well as file. Looking at the large documentation on log4j I was able to add the appender as shown in the code below. However I don't seem to be getting logs in the specified file.
Any ideas what might be wrong? Here is my log4j.xml (already located at src/)
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE log4j:configuration SYSTEM "log4j.dtd">
<log4j:configuration xmlns:log4j="http://jakarta.apache.org/log4j/" debug="false">
<appender name="CONSOLE" class="org.apache.log4j.ConsoleAppender">
<param name="Threshold" value="DEBUG"/>
<param name="Target" value="System.out"/>
<layout class="org.apache.log4j.PatternLayout">
<param name="ConversionPattern" value="%d{ABSOLUTE} %-5p [%c{1}] %m%n"/>
</layout>
</appender>
<appender name="FILE" class="org.apache.log4j.RollingFileAppender">
<param name="append" value="false" />
<param name="file" value="/data/MFlogs/log.log"/>
<param name="immediateFlush" value="true"/>
<param name="threshold" value="debug"/>
<layout class="org.apache.log4j.PatternLayout">
<param name="ConversionPattern" value="%d{ABSOLUTE} %-5p [%c{1}] %m%n"/>
</layout>
</appender>
<root>
<priority value="DEBUG" />
<appender-ref ref="CONSOLE"/>
<appender-ref ref="FILE"/>
</root>
</log4j:configuration>

change file path tag. try it with double slash.
value="//data//MFlogs//log.log"

Try adding full path to path location or add ${catalina.home}/logs/myApp.log to it.
Read this question, it tells how to use relative path. It is easy if you use properties file instead of xml file.

log4j smtp appender overriding gives unexpected behavior?

I have overridden log4j smtp appender for some purpose. The problem is if i keep <param name="Threshold" value="INFO"/> Then it would send mails properly. But if i keep <param name="Threshold" value="ERROR"/> Then no mails are sent. What is the problem? Please find my code.
public class MyAppender extends SMTPAppender{
#Override
protected void sendBuffer() {
//Some code to format email body
}
}
log4j.xml
<!-- Appenders -->
<appender name="mail" class="com.service.MyAppender">
<param name="BufferSize" value="2"/>
<param name="BufferedIO" value="true"/>
<param name="Threshold" value="ERROR"/>
<param name="SMTPHost" value="myhost"/>
<param name="From" value="abc#co.com"/>
<param name="To" value="def#ld.com"/>
<param name="Subject" value="Testing Testing"/>
<layout class="org.apache.log4j.PatternLayout">
<param name="ConversionPattern"
value="%d{yyyy-MM-dd HH:mm:ss} %-5p %c{2}:%L - %m%n"/>
</layout>
</appender>
<appender name="ASYNC" class="org.apache.log4j.AsyncAppender">
<param name="BufferSize" value="500"/>
<appender-ref ref="mail"/>
</appender>
<root>
<level value="ERROR" />
<appender-ref ref="ASYNC" />
</root>
I looked into SMTPAppender source code and i believe below lines are the problem.
if(evaluator.isTriggeringEvent(event)) {
sendBuffer();
}

According to log4j documentation, all log events with value lower than Treshold will be filtered out (i.e. not sent).
It's possible that changing Treshold to more restrictive filters out all messages that are logged in your case.
Make sure that you actually have events with log level ERROR (or higher - FATAL).

Email log4j errors to different groups

Am using log4j for my error reporting. Ive set my log 4j to also append errors to emails. However i need it to send emails to separate groups depending on the level of the message. For example
info messages go to management- john#management.com, peter#management.com, simon#management.com
debug messages go to programmers - paul#programmer.com, matt#programmer.com
warn messages go to administrator - admin#admin.com
In such a fashion, is it possible? And has anyone implemented said procedure (a sample properties file would be appreciated)

Is should be easy to configure something like this using the SMTPAppender from log4j. But be aware, that emailing logs takes quite a bit of load, especially if you consider mailing DEBUG reports to developers.

You can use a log4j Filter to do this (http://logging.apache.org/log4j/1.2/apidocs/org/apache/log4j/spi/Filter.html)
The example below writes messages to different files according to the log level.
This can be easily adapted to an SMTPAppender instead of a FileAppender.
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE log4j:configuration SYSTEM "log4j.dtd">
<log4j:configuration xmlns:log4j='http://jakarta.apache.org/log4j/'>
<appender name="management" class="org.apache.log4j.FileAppender">
<param name="File" value="management.log" />
<layout class="org.apache.log4j.PatternLayout">
<param name="ConversionPattern" value="%m"/>
</layout>
<filter class="org.apache.log4j.varia.LevelRangeFilter">
<param name="LevelMin" value="INFO" />
<param name="LevelMax" value="INFO" />
<param name="AcceptOnMatch" value="true" />
</filter>
</appender>
<appender name="programmers" class="org.apache.log4j.FileAppender">
<param name="File" value="programmers.log" />
<layout class="org.apache.log4j.PatternLayout">
<param name="ConversionPattern" value="%m"/>
</layout>
<filter class="org.apache.log4j.varia.LevelRangeFilter">
<param name="LevelMin" value="DEBUG" />
<param name="LevelMax" value="DEBUG" />
<param name="AcceptOnMatch" value="true" />
</filter>
</appender>
<appender name="admin" class="org.apache.log4j.FileAppender">
<param name="File" value="admin.log" />
<layout class="org.apache.log4j.PatternLayout">
<param name="ConversionPattern" value="%m"/>
</layout>
<filter class="org.apache.log4j.varia.LevelRangeFilter">
<param name="LevelMin" value="WARN" />
<param name="LevelMax" value="WARN" />
<param name="AcceptOnMatch" value="true" />
</filter>
</appender>
<category name="a">
<level value="ALL" />
<appender-ref ref="management"/>
<appender-ref ref="programmers"/>
<appender-ref ref="admin"/>
</category>
</log4j:configuration>

Log4j Maxfilesize

Problem i have with log4j is that when i specify maxfilesize it works properly for the files generated in the src folder of project, but the log files generated in tomcat bin, are not splited into seperate files and then i have a large log file which is not desirable.
The following is log4j.xml:
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE log4j:configuration SYSTEM "log4j.dtd" >
<log4j:configuration>
<appender name="fatalFile" class="org.apache.log4j.RollingFileAppender">
<param name="MaxFileSize" value="100KB" />
<param name="MaxBackupIndex" value="5" />
<param name="File" value="logs/pnusn/fatal.log" />
<param name="threshold" value="fatal" />
<layout class="org.apache.log4j.PatternLayout">
<param name="ConversionPattern" value="%5p in Class:%C{2}, Thread:%t, at:%d{ABSOLUTE}:: '%m'%n" />
</layout>
</appender>
<appender name="othersFile" class="org.apache.log4j.RollingFileAppender">
<param name="MaxFileSize" value="100KB" />
<param name="MaxBackupIndex" value="5" />
<param name="File" value="logs/pnusn/others.log" />
<layout class="org.apache.log4j.PatternLayout">
<param name="ConversionPattern" value="%5p in Class:%C{2}, Thread:%t, at:%d{ABSOLUTE}:: '%m'%n" />
</layout>
<filter class="org.apache.log4j.varia.LevelRangeFilter">
<param name="LevelMin" value="debug" />
<param name="LevelMax" value="error" />
</filter>
</appender>
<appender name="traceFile" class="org.apache.log4j.RollingFileAppender">
<param name="MaxFileSize" value="200KB" />
<param name="MaxBackupIndex" value="20" />
<param name="File" value="logs/pnusn/trace.log" />
<layout class="org.apache.log4j.PatternLayout">
<param name="ConversionPattern" value="%5p in Class:%C{2}, Thread:%t, at:%d{ABSOLUTE}:: '%m'%n" />
</layout>
<filter class="org.apache.log4j.varia.LevelRangeFilter">
<param name="LevelMin" value="trace" />
<param name="LevelMax" value="trace" />
</filter>
</appender>
<root>
<priority value="trace"></priority>
<appender-ref ref="fatalFile" />
<appender-ref ref="othersFile" />
<appender-ref ref="traceFile" />
</root>
</log4j:configuration>
Does anybody know how can i fix it?
Thanks for your consideration.

The log4j log files are appearing in your tomcat's bin directory because you haven't told it to do otherwise.
The tomcat docs here describe how to integrate log4j, including the use of the ${catalina.out} substitution to refer to the tomcat root directory. The instructions refer to the log4j properties file format, too, it's not clear if it'll work for log4j.xml
As for the file size problem, I'm not sure why that's happening. Try using the DailyRollingFileAppender instead, and see if that works.