[Log4j] log 4 j 설정방법 (Servlet)

* Log4j 설정방법

1. log4j.jar 를 Download 받아 lib 폴더에 붙혀 넣는다.

2. log4j.properties 파일을 아래와 같이 작성해준다.

   ( 옵션에 대한 설명은 생략 )

###############################################################################

#

# log4j  

#

###############################################################################

log4j.rootLogger = DEBUG, stdout, dailyfile

# Console Appender 

log4j.appender.console.Threshold = DEBUG

log4j.appender.console=org.apache.log4j.ConsoleAppender

log4j.appender.console.layout=org.apache.log4j.PatternLayout

log4j.appender.console.layout.ConversionPattern=%d %p [%c] - %m%n

# Console output... 

log4j.appender.stdout.Threshold = DEBUG

log4j.appender.stdout = org.apache.log4j.ConsoleAppender 

log4j.appender.stdout.layout = org.apache.log4j.PatternLayout 

log4j.appender.stdout.layout.ConversionPattern = [%d{MMdd HHmmss}] %5p %F:%L:%M - %m%n 

# Daily file log

log4j.appender.dailyfile.Threshold = DEBUG

log4j.appender.dailyfile = org.apache.log4j.DailyRollingFileAppender 

log4j.appender.dailyfile.DatePattern = '.'yyyy-MM-dd

log4j.appender.dailyfile.layout = org.apache.log4j.PatternLayout 

log4j.appender.dailyfile.layout.ConversionPattern =[%d{MMdd HHmmss}] %5p %F:%L:%M - %m%n

log4j.appender.dailyfile.File = ${catalina.home}/logs/testLog.log   <- 로그파일 경로

#절대경로혹은  상대경로를 사용

3. log4j.properties 파일을 설정된 Classpath(보통 : WEB-INF/classes/)안에 넣어준 후 

     /WEB-INF/web.xml 에 아래를 추가한다.

<servlet> 

     <servlet-name>log4j-init</servlet-name>

     <servlet-class>com.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> 

     

4. Log4jInit.java 추가

package com;

import org.apache.log4j.PropertyConfigurator;

import javax.servlet.http.HttpServlet; 

public class Log4jInit extends HttpServlet {

 

 public void init()

 {

     String prefix =  getServletContext().getRealPath("/");

     String file = getInitParameter("log4j-init-file");

  

     // if the log4j-init-file context parameter is not set, then no point in trying

     if(file != null){

      PropertyConfigurator.configure(prefix+file);

      System.out.println("Log4J Logging started: " + prefix+file);

     }

     else{

      System.out.println("Log4J Is not configured for your Application: " + prefix + file);

     }     

 }

}

    

5. 로그가 찍히는 지 확인

TestServlet.java

import java.io.IOException;

import java.io.PrintWriter;

import javax.servlet.ServletException;

import javax.servlet.annotation.WebServlet;

import javax.servlet.http.HttpServlet;

import javax.servlet.http.HttpServletRequest;

import javax.servlet.http.HttpServletResponse;

import org.apache.log4j.Logger;

@WebServlet("/testServlet")

public class testServlet extends HttpServlet {

private Logger log = Logger.getLogger(testServlet.class);   

protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {

System.out.println("test");

log.debug("test logger " );

}

}