Log4j in Servlets

[Kedar Kachare]

How to use Log4j to create log files using file appender in a Servlet? Also, how to make that Servlet read the log4j.propertie s file?


I have tried following:

My web.xml( I use Eclipse europa)

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://java.sun.com/xml/ns/javaee" xmlns:web="http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" id="WebApp_ID" version="2.5">
 
        <display-name>ClientSkill_Log4j</display-name>
 
        <welcome-file-list>
 
          <welcome-file>index.html</welcome-file>
 
          <welcome-file>index.htm</welcome-file>
 
          <welcome-file>index.jsp</welcome-file>
 
          <welcome-file>default.html</welcome-file>
 
          <welcome-file>default.htm</welcome-file>
 
          <welcome-file>default.jsp</welcome-file>
 
        </welcome-file-list>
 
 
 
        <servlet>
 
          <description>Description</description>
 
          <display-name>Display name</display-name>
 
 
          <servlet-name>ClientSkillServlet</servlet-name>
 
          <servlet-class>HTML_Generator</servlet-class>
 
 
 
          <init-param>
 
              <param-name>log4j.properties</param-name>
 
              <param-value>WEB-INF/log4j.properties</param-value>
 
          </init-param>
 
        </servlet>
 
 
 
        <servlet-mapping>
 
          <servlet-name>ClientSkillServlet</servlet-name>
 
          <url-pattern>/</url-pattern>
 
        </servlet-mapping>
</web-app>
 

My log4j.propertie s file:-

 
      # Configures Log4j as the Tomcat system logger
      #
      #
      # Configure the logger to output info level messages into a log file.
      #
      log4j.rootLogger=INFO, R
      #
      # To continue using the "catalina.out" file (which grows forever),
      # comment out the above line and uncomment the next.
      #
      log4j.rootLogger=ERROR, A1
      #
      # Configuration for standard output ("catalina.out").
      #
      log4j.appender.A1=org.apache.log4j.ConsoleAppender 
      log4j.appender.A1.layout=org.apache.log4j.PatternL  ayout
      #
      # Print the date in ISO 8601 format
      #
      log4j.appender.A1.layout.ConversionPattern=%d [%t] %-5p %c - %m%n
      #
      # Configuration for a rolling log file ("tomcat.log").
      #
      log4j.appender.R=org.apache.log4j.FileAppender
      # Edit the next line to point to your logs directory.
      # The last part of the name is the log file name.
      #
      log4j.appender.R.File=D:\DATA\tomcat.log
      log4j.appender.R.layout=org.apache.log4j.PatternLa  yout
      #
      # Print the date in ISO 8601 format
      #
      log4j.appender.R.layout.ConversionPattern=%d [%t] %-5p %c - %m%n
      # Application logging options
      #
      #log4j.logger.org.apache=DEBUG
      #log4j.logger.org.apache=INFO
      #log4j.logger.org.apache.struts=DEBUG
      #log4j.logger.org.apache.struts=INFO
 

and My servlet code is:

      import java.sql.*;
      import java.io.*;
      import javax.servlet.*;
      import javax.servlet.http.*;
      import org.apache.log4j.*;
 
      public class HTML_Generator extends HttpServlet
 
      {
          private static Logger logger =Logger.getLogger(HTML_Generator.class);
          public void init() throws ServletException
 
          {
 
              // Put your code here
 
              String prefix = getServletContext().getRealPath("/");
 
              String file = getInitParameter("log4j.properties");
 
              if(file != null)
 
              {
 
                  PropertyConfigurator.configure(prefix+file);
              }
 
          }
 
          public void doPost(HttpServletRequest req,HttpServletResponse resp) throws ServletException, IOException
 
          {
 
                  PrintWriter pw = resp.getWriter();
 
                  Connection conn = null;
 
                  ResultSet rs = null;
 
                  Statement stmt = null;
 
                  pw.println("Check your web server console...");
 
                  System.out.println("Insde doPost()");
 
                  pw.flush();
 
                  pw.close();
 
                  try
 
                  {
 
                      Class.forName("<driver name>");
 
                      conn = DriverManager.getConnection("<url>","<username>","<password>");
 
                      stmt = conn.createStatement();
 
                      rs = stmt.executeQuery("<my query>" );
 
                      int numColumns = rs.getMetaData().getColumnCount();
 
                      int i=0;
 
                      pw.println("<form name=\"Form2\" method=\"POST\" action=\"http://localhost/servlet/<target-servlet(running fine)>\">");
 
                      while (rs.next())
 
                      {
 
                          for (i = 1 ; i < numColumns ; i++ )
 
                              {
 
                                  <my action>
 
                              }
 
                      }
 
 
 
                  }
 
                  catch(SQLException sqle)
 
                  {
 
                      sqle.printStackTrace();
 
                  }
 
                  catch(Exception exc)
 
                  {
 
                      exc.printStackTrace();
 
                  }
 
                  try
 
                  {
 
                      rs.close();
 
                      stmt.close();
 
                      conn.close();
 
                  }catch(SQLException sqle){
 
                      sqle.printStackTrace();
 
                  }catch(Exception exc){
 
                      exc.printStackTrace();
 
                  }
 
          }
 
      }
 

Thanks in advance,
Kedar

[Dököll]

Greetings!

I fetched below and thought it could be of use:

Using the Log4J

http://www.roseindia.net/tutorials/l...er-log4j.shtml

Let us know if it worked:-)