How to Specify the Log File address as RootDir/Logs/Error.log in Log4j

Question

I have a web application,
How to configure the log4j Rolling file Appender in that.
I want to logs to be redirected to the RootDir/logs/Error.log.
Currently, I m using following configuration:
# This file must live on the classpath of the jvm
# Set root logger level to DEBUG and log to both stdout and rollingFile appenders
# (see below for their definitions)
# The set of possible levels are: DEBUG, INFO, WARN, ERROR and FATAL
log4j.rootLogger=INFO, stdout, R
####### Console appender ######
log4j.appender.stdout=org.apache.log4j.ConsoleAppender
log4j.appender.stdout.layout=org.apache.log4j.PatternLayout
# Pattern to output the caller's file name and line number.
# The pattern: Date Priority (Filename:Line Number) - Message\n
log4j.appender.stdout.layout.ConversionPattern=%d %-5p (%F:%L) - %m%n
#### Second appender writes to a file
log4j.appender.R=org.apache.log4j.RollingFileAppender
log4j.appender.R.File=Error.log
# Control the maximum log file size
log4j.appender.R.MaxFileSize=100KB
# Archive log files (one backup file here)
log4j.appender.R.MaxBackupIndex=1
log4j.appender.R.layout=org.apache.log4j.PatternLayout
log4j.appender.R.layout.ConversionPattern=%d %-5p (%F:%L) - %m%n
Thanks for your replies in advance.

Answer 1

Please follow the following steps, will work.
To enable log4j logging to a file on lunar pages do the following:
1) Create a servlet class that will initialize log4j. Here is
the code:
package logging;
import org.apache.log4j.PropertyConfigurator;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
public class Log4jInit extends HttpServlet {
public
void init() {
String prefix = getServletContext().getRealPath("/");
String file = getInitParameter("log4j-init-file");
// if the log4j-init-file is not set, then no point in trying
if(file != null) {
PropertyConfigurator.configure(prefix+file);
public
void doGet(HttpServletRequest req, HttpServletResponse res) {
2) In your web.xml file add the following entry:
<servlet>
<servlet-name>log4j-init</servlet-name>
<servlet-class>logging.Log4jInit</servlet-class>
<init-param>
<param-name>log4j-init-file</param-name>
<param-value>WEB-INF/classes/log4j.lcf</param-value>
</init-param>
<load-on-startup>1</load-on-startup>
</servlet>
3) Create a log4j.lcf file located in your WEB-INF/classes directory
as with the following entries:
log4j.rootLogger=debug, R
# yourdirectory below is where your site lives.
log4j.appender.R=org.apache.log4j.RollingFileAppender
log4j.appender.R.File=/home/yourdirectory/public_html/logs/out.log
log4j.appender.R.MaxFileSize=500KB
# Keep one backup file
log4j.appender.R.MaxBackupIndex=1
log4j.appender.R.layout=org.apache.log4j.PatternLayout
log4j.appender.R.layout.ConversionPattern=%d %-5p [%c] %m%n
4) Add logging to your class. Here is an example:
import org.apache.log4j.Logger;
public class Example {
static Logger logger = Logger.getLogger(Example.class);
public void doSomething() {
logger.debug("testing logging");
5) make sure you have the log4j-1.2.8.jar file located in your WEB-INF/lib directory.
That should do it!