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Error using log4j in webapp

Greenhorn

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posted 16 years ago

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Hi all, I'm a beginner to web application
I tried to create a simple web application, namely WebTest. It only contains one servlet, like this:

package solmit;

import java.io.IOException;
import java.io.PrintWriter;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.apache.log4j.Logger;;

public class WebTest extends HttpServlet {
private static Logger log = Logger.getLogger(WebTest.class);

public void doGet(HttpServletRequest request, HttpServletResponse response)
throws IOException, ServletException
{
log.debug("anas: about to enter doGet");
response.setContentType("text/html");
PrintWriter writer = response.getWriter();

writer.println("<html><head><title>Simple Web Application</title></head>");
writer.println("<body><h1>A Simple Web Application</h1>");
writer.println("Here's some text...<br>...and a bit more text");
writer.println("</body></html>");
log.debug("anas: about to leave doGet");
}
}

My web.xml file looks like this:

I also created log4j.properties file in <web-app>/WEB-INF/classes directory. It contains the following code:

I packaged this application into WebTest.war.
When I dropped this package into my Tomcat (Tomcat 5.5), and tried to access web app using this url :http://localhost:8080/WebTest/start-web-test
I got error messages on my stderr_20080522 log:

Oh, I've also dropped log4j-1.2.13.jar and commons-logging-1.0.4.jar on Tomcat/common/lib
I've read tomcat documentation on logging.. but it seems that it doesn't give me some clue to use log4j logging in my application ("http://localhost:8080/tomcat-docs/logging.html")
I've also already read the documentation about log4j on "http://www.laliluna.de/log4j-tutorial.html"
Could someone give an insight on this ??
Any help would be appreciated
Spec:
Tomcat 5.5
Jre 1.5.0_15
Windows XP Prof edition
Thanks

Ben Souther

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posted 16 years ago

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"anas java",
Please check your private messages.
-Ben

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Anas Nashroel

Greenhorn

Posts: 12

posted 16 years ago

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Hi Ben,
Thanks for the reply. After I changed as what you said, I managed to display the output from the servlet. But, the error log4j configuration still remains..and no debug messages appear on my log file.
Error from stderr_20080522.log:

log4j:WARN No appenders could be found for logger (org.apache.catalina.startup.Embedded).
log4j:WARN Please initialize the log4j system properly.

How do we actually setup log4j in our web apps ??
Does anyone have the same experience ??
Thanks

Ben Souther

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posted 16 years ago

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Where did you put your log4j.properties file?

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Anas Nashroel

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posted 16 years ago

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I put it in <my-web-app>/WEB-INF/classes on my web application

Ben Souther

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posted 16 years ago

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Can you post your log4j.properties file?

Java API J2EE API Servlet Spec JSP Spec How to ask a question... Simple Servlet Examples jsonf

Anas Nashroel

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posted 16 years ago

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Here's my log4j.properties file:

log4j.logger.solmit=ALL, A
log4j.logger.org.apache=OFF, A

log4j.appender.A=org.apache.log4j.ConsoleAppender
log4j.appender.A.layout=org.apache.log4j.PatternLayout
log4j.appender.R.layout.ConversionPattern=%p %t %c - %m%n

The problem is already solved, Ben...
Actually, I followed the instruction on log4j docs..
I created initialization servlet, Log4jInit.class, that initializes log4j and loaded on startup...
This initialization class looks like this:

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) {
}
}

and adding this entry to web.xml file:

<servlet>
<servlet-name>log4j-init</servlet-name>
<servlet-class>com.foo.Log4jInit</servlet-class>

<init-param>
<param-name>log4j-init-file</param-name>
<param-value>WEB-INF/classes/log4j.properties</param-value>
</init-param>

<load-on-startup>1</load-on-startup>
</servlet>

In the class above, the static method configure(java.util.Properties properties) of PropertyConfigurator class is called to initialize log4j

When the tomcat starts, the logs are printed to stderr_20080522.log

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