Log4j in a web application

[Miguel Flecha]

Hi all. I have a problem with log4j in my webapp.
This is my config file:

log4j.rootCategory=ALL, A1
log4j.appender.A1=org.apache.log4j.FileAppender
log4j.appender.A1.File=F:/ibt/logs/ibt.log
log4j.appender.A1.MaxFileSize=1024KB
# Keep one backup file
log4j.appender.A1.MaxBackupIndex=1
log4j.appender.A1.layout=org.apache.log4j.PatternLayout
log4j.appender.A1.layout.ConversionPattern=%p %t %c - %m%n

I just want to know how to config the web.xml to use this file, as I get this error:

log4j:WARN No appenders could be found for logger (org.apache.struts.util.PropertyMessageResources).
log4j:WARN Please initialize the log4j system properly.

Sorry, but I'm new with Log4j
Regards
Miguel

[din dee]

Log4j is used for Logging .,It is do Appender,Layout(design the o/p ) for logging information. using log4j.xml ., it has file tag u assign where u can store it.

[Miguel Flecha]

Could you explain me how to do it?

[Miguel Flecha]

something like this?

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

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

<!-- LOGS => Consola -->
<appender name="stdout" class="org.apache.log4j.ConsoleAppender">
<layout class="org.apache.log4j.PatternLayout">
<param name="ConversionPattern" value="%d %-5p %C{2} - %m%n"/>
</layout>
</appender>

<appender name="org.apache.struts.util.PropertyMessageResources" class="org.apache.log4j.RollingFileAppender">
<param name="File" value="F:/ibt/ibt2.log"/>
<param name="MaxFileSize" value="1024KB"/>
<param name="MaxBackupIndex" value="10"/>
<layout class="org.apache.log4j.PatternLayout">
<param name="ConversionPattern" value="%d %-5p %C{2} - %m%n"/>
</layout>
</appender>


How do I modify web.xml now?
Thanks
Miguel

[Pavan Panduga]

Miguel,

if you're using Tomcat, place your log4jconfig.xml file in WEB-INF/classes directory and log4j.jar in the lib directory. Taht will initialize Log4J.

If you want to use a special Servlet,
this might help.

  
package com.test.logging;
public class InitializeLogging extends HttpServlet{
     public void init(){
       String prefix = getServletContext().getRealPath("/");
       String filename= getInitParameter("log4j-config-file");
       if( filename != null ){
          PropertyConfigurator.configure( prefix+filename );
       }
     }
    public void doGet( HttpServletRequest req, HttpServletResponse res ){
    }
}

you web.xml should have

  
  <servlet>
    <servlet-name>log4j-init</servlet-name>
    <servlet-class>com.test.logging.InitializeLogging</servlet-class>
    <init-param>
      <param-name>log4j-config-file</param-name>
      <param-value>WEB-INF/classes/log4j.properties</param-value>
    </init-param>
    <load-on-startup>1</load-on-startup>
  </servlet>

if you have an xml config file, use DOMConfigurator instead of PropertyConfigurator.

Hope this helps,
Regards,

[Miguel Flecha]

Hi Paval!!
I haven't answered before because I just came from holidays. Thanks for your help!
The problem I have is that prefix = getServletContext().getRealPath("/"); returns null. If I set the prefix this way : prefix= "F:\ibt\logs\" it works perfectly
What am I doing wrong?
Regards
Miguel

[H Shah]

I'm trying the same thing as Miguel, but I'm running into a different problem. I want to use Log4J in my web app, but whenever I try to get a logger, JCL returns the Jdk14Logger instead.

Here's my setup:

<tomcat_dir>\common\lib does not contain commons-logging.jar or log4j.jar
<mywebapp>\WEB-INF\lib contains commons-logging.jar and log4j.jar

I have an initialization servlet that reads the log4j xml config file:


private void initializeLogging() {
BasicConfigurator.configure();

DOMConfigurator.configure(log4jConfigFilename);

Log jclLog = LogFactory.getLog(EnvironmentInitializer.class);
jclLog.debug("Debug statement");
jclLog.info("Info statement");
jclLog.error("Error statement");
jclLog.fatal("Fatal statement");
}


and here's my output:


Sep 22, 2004 1:11:54 PM log4jconfig.EnvironmentInitializer initializeLogging
INFO: Info statement
Sep 22, 2004 1:11:54 PM log4jconfig.EnvironmentInitializer initializeLogging
SEVERE: Error statement
Sep 22, 2004 1:11:54 PM log4jconfig.EnvironmentInitializer initializeLogging
SEVERE: Fatal statement





Any help would be greatly appreciated. Thanks!!

-Hitesh