Eclipse + Tomcat + log4j (xml, properties) w/ slf4j

1. [web.xml] servlet 등록 (지정한 param-value 경로에 log4j.xml 또는 log4j.properties 있어야 함)

...

<servlet>

<servlet-name>Log4JInitServlet</servlet-name>

<servlet-class>lawmin.util.Log4JInitServlet</servlet-class>

<init-param>

<param-name>log4j-conf-location</param-name>

<param-value>WEB-INF/classes/log4j.xml</param-value>

</init-param>

<load-on-startup>4</load-on-startup>

</servlet>

...

2. [Log4JInitServlet] class, jar 생성 (xml 또는 properties 를 읽음)

package lawmin.util;

import java.io.File;

import javax.servlet.ServletConfig;

import javax.servlet.ServletContext;

import javax.servlet.ServletException;

import javax.servlet.http.HttpServlet;

import org.apache.log4j.BasicConfigurator;

import org.apache.log4j.PropertyConfigurator;

import org.apache.log4j.xml.DOMConfigurator;

public class Log4JInitServlet extends HttpServlet {

private static final long serialVersionUID = 1L;

@Override

public void init(ServletConfig config) throws ServletException {

System.out.println("[log4j] Initializing...");

String log4jLocation = config.getInitParameter("log4j-conf-location");

ServletContext sc = config.getServletContext();

if (log4jLocation == null) {

System.err.println("[log4j] log4j-conf-location parameter not specified. Initialize with BasicConfigurator");

BasicConfigurator.configure();

} else {

String webAppPath = sc.getRealPath("/");

String log4jConfPath = webAppPath + log4jLocation;

File file = new File(log4jConfPath);

if (file.exists()) {

System.out.println("Initializing log4j with: " + log4jConfPath);

if(log4jLocation.endsWith(".properties")) {

PropertyConfigurator.configure(log4jConfPath);

}

else if(log4jLocation.endsWith(".xml")) {

DOMConfigurator.configure(log4jConfPath);

}

else {

System.err.println("[log4j] no xml or properties file specified. Initialize with BasicConfigurator");

BasicConfigurator.configure();

}

}

else {

System.err.println("[log4j] " + log4jConfPath + " not found. Initialize with BasicConfigurator");

BasicConfigurator.configure();

}

}

super.init(config);

}

}

3. [log4j.xml] 샘플

<?xml version="1.0" encoding="UTF-8"?>

<!DOCTYPE log4j:configuration PUBLIC "-//LOGGER" "log4j.dtd">

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

    <!-- Appenders -->

    <appender name="console-debug" class="org.apache.log4j.ConsoleAppender">

        <param name="Target" value="System.out" />

        <layout class="org.apache.log4j.PatternLayout">

            <param name="ConversionPattern" value="[%d{yyyy-MM-dd HH:mm:ss}] %5p [%c.%M(%L)] %m %n" />

        </layout>

    </appender>

    <appender name="console-info" class="org.apache.log4j.ConsoleAppender">

        <param name="Target" value="System.out" />

        <layout class="org.apache.log4j.PatternLayout">

            <param name="ConversionPattern" value="[%d{yyyy-MM-dd HH:mm:ss}] %5p (%F[%M]:%L) - %m%n" />

        </layout>

    </appender>

    <!-- 3rd party Loggers -->

    <logger name="lawmin.manager">

        <level value="error" />

    </logger>

    <root>

        <priority value="debug" />

        <appender-ref ref="console-debug" />

    </root>

    

</log4j:configuration>

4. [Log4JInitServlet.jar] 를 Eclipse - Run Configurations - Server - Apache Tomcat - 해당 서버 선택 - Classpath - User Entries - Add JARs 또는 Add External JARs 로 추가

5. 서버 시작하면 로그가 설정한 규칙대로 떨어지는 것을 확인할 수 있다.