log4j.xml example – Log4j xml configuration example

I want only fresh logs to be generated in my Log file each time when I run any scripts.
Can you help on this what changes needs to be done in .xml file.

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE log4j:configuration PUBLIC "-//LOG4J//DTD CONFIGURATION//EN" "http://logging.apache.org/log4j/docs/api/org/apache/log4j/xml/log4j.dtd">


<log4j:configuration xmlns:log4j="http://jakarta.apache.org/log4j/" debug="false">

    <appender name="defaultLog" class="org.apache.log4j.DailyRollingFileAppender">
        <param name="File" value="${log.path}\fcm.log" />
        <param name="append" value="true" />                  
        <param name="encoding" value="UTF-8" />  
        <param name="DatePattern" value="'.'MM-dd-yyyy" />   
        <layout class="org.apache.log4j.PatternLayout">
			<param name="ConversionPattern" value="[%-5p:%t][%X{USERID}][%X{SESSIONID}][%d{MM-dd-yyyy HH:mm:ss,SSS a Z}]%-c{1}: %n%m%n"/>
        </layout>
    </appender>

    <root>
		<level value="info" />
		<appender-ref ref="defaultLog" />
	</root>
</log4j:configuration>

This looks correct to me. Also by using:
private static Logger log = Logger.getLogger(ClassName.class);

log.info does work and does write to the log file.

But every time I start WebSphere Server I see in red:
log4j:WARN No appenders could be found for logger (org.apache.ibatis.logging.LogFactory).
log4j:WARN Please initialize the log4j system properly.
log4j:WARN See http://logging.apache.org/log4j/1.2/faq.html#noconfig for more info.

Also, Log4j.xml is under WEB-INF and log4j-1.2.16.jar is in the Java Build Path/Libraries.

Can you tell me what is wrong with this setup ?

I have given only %m%n in my conversionPattern, but im getting a lot of data. why is that?

Hi Sir,

Actually we want to dynamic value from java code to print on every line of log file.

Hi,

Thanks for sharing this.

How can I log all console output to a file ?
Console output like all the system output i.e system.out.print,system.err.print and all jvm related error/exceptions.

Could you please help me here.

Thanks,
Wasim

Hi Lokesh!

I’m new to log4j config. What I’m trying to do is add server name/hostname to the file name of the appender.
Indeed I have the same EAR deployed into 2 different servers (a cluster) using Weblogic and I need server name/hostname to be replaced by the name of each server during start up of the app.
I hope I’ve made myself clear.
Can you help here?
Here is the code:

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE log4j:configuration SYSTEM "log4j.dtd">
<log4j:configuration xmlns:log4j="http://jakarta.apache.org/log4j/" debug="true" threshold="debug">

    <appender name="STDOUT" class="org.apache.log4j.ConsoleAppender">
        <layout class="org.apache.log4j.PatternLayout">
            <param name="ConversionPattern" value="%-4r %-5p [%t] %37c %3x - %m%n"/>
        </layout>
    </appender>

    <appender name="DFe" class="org.apache.log4j.RollingFileAppender">
        <param name="File" value="servers/${weblogic.Name}/logs/dfe_${HERE I WANT TO ADD SERVER NAME/HOSTNAME}.log"/>
        <param name="Append" value="true"/>
        <param name="MaxFileSize" value="10000KB"/>
        <param name="MaxBackupIndex" value="10"/>

        <layout class="org.apache.log4j.PatternLayout">
            <param name="ConversionPattern" value="%X{version} - %d %-5p [%c] %m%n"/>
        </layout>
    </appender>

    <logger name="br.com.synchro.dfe" additivity="false">
        <level value="debug"/>
        <appender-ref ref="DFe"/>
    </logger>

    <root>
        <priority value="error"/>
        <appender-ref ref="DFe"/>
    </root>
</log4j:configuration>

Thanks in advance.
Paulo

I am seeing org.xml.sax.SAXParseException; systemId: file:/E:/Fresh%20Start/Practise%20Concepts%20Advanced/log4j-config.xml; lineNumber: 20; columnNumber: 35; The element type “appender-ref” must be terminated by the matching end-tag “”.
at org.apache.xerces.parsers.DOMParser.parse(Unknown Source)
at org.apache.xerces.jaxp.DocumentBuilderImpl.parse(Unknown Source)
at javax.xml.parsers.DocumentBuilder.parse(DocumentBuilder.java:205)
at org.apache.log4j.xml.DOMConfigurator$1.parse(DOMConfigurator.java:749)
at org.apache.log4j.xml.DOMConfigurator.doConfigure(DOMConfigurator.java:871)
at org.apache.log4j.xml.DOMConfigurator.doConfigure(DOMConfigurator.java:755)
at org.apache.log4j.xml.DOMConfigurator.configure(DOMConfigurator.java:896)
at log4jdemo.Log4jFromXML.main(Log4jFromXML.java:13)

And my xml file looks like

<!DOCTYPE log4j:configuration SYSTEM "log4j.dtd">
<log4j:configuration debug="true" xmlns:log4j='http://jakarta.apache.org/log4j/'>
 
  <appender name="console" class="org.apache.log4j.ConsoleAppender">
    <param name="Target" value="System.out"/>
    <layout class="org.apache.log4j.PatternLayout">
    <param name="ConversionPattern" value="%d{yyyy-MM-dd HH:mm:ss} %-5p %c{1}:%L - %m%n" />
    </layout>
  </appender>
 
  <appender name="fileAppender" class="org.apache.log4j.RollingFileAppender">
    <param name="File" value="demoApplication.log"/>
    <layout class="org.apache.log4j.PatternLayout">
    <param name="ConversionPattern" value="%d{yyyy-MM-dd HH:mm:ss} %-5p %c{1}:%L - %m%n" />
    </layout>
  </appender>
 
  <root>
    <priority value ="debug"></priority>
    <appender-ref ref="console"></appender>
    <appender-ref ref="fileAppender"></appender>
  </root>
 
</log4j:configuration>

As same as given above. Please tell me what shall i do ?

Hi,

there is a possibility of a load a parameter file within properties the log4j.xml . I am using WebLogic Server within the server and have the search.properties file within the file and have routAux = / my / dir / out / so that in the log4j.xml can do something like this

within the log4j.xml x. I am using WebLogic Server within the server and have the search.properties arhivo within the file and have routAux = / my / dir / out / so that in the log4j.xml can do something like this

HI,
Thanks for posting this.
I am new to the log4j configuration. The problem I am facing is, while printing the loggers on the server log I am getting %3D, %2C type of character instead of = & , characters & so on.
I tried to put , but still problem is remaining as it is.
Can you please guide me how to resolve this issue.
When I searched on google, I came to know It’s encoding issue.

Please suggest.
Thanks,

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE log4j:configuration SYSTEM "log4j.dtd" >
<log4j:configuration>

<appender name="file" class="org.apache.log4j.RollingFileAppender">
		<param name="maxFileSize" value="10MB" />
		<param name="maxBackupIndex" value="500000" />

		<param name="File" value="C:/LOGS/test.log" />
		<param name="threshold" value="info" />
		<layout class="org.apache.log4j.PatternLayout">
			<param name="ConversionPattern" value="%d %5p %c{1}:%L - %m%n" />
		</layout>
	</appender>

<root>
		<priority value="debug"></priority>
		<appender-ref ref="errorfile" />
		<appender-ref ref="debugfile" />
		<appender-ref ref="file" />
	</root>


</log4j:configuration>

Hi below is my log4j.xml snippet, when my web application is deployed in websphere, log files are getting overwritten instead of backup files. Kindly guide me.

Where save the files with this configuration?

is it possible to code the entire log4j java file without xml and without properties if yes then please upload and update me