log4j的配置文件和继承？

Question

I have trouble to understand configuration of log4j when several configuration files are used.

I explain my case:

• I have simple a Java EE app with modules (web, ejb, jpa)
• I have also custom server authentication module (SAM) to handle security with Glassfish, I don't use realm directly in my app.

So, I have 2 xml configuration files because my SAM (JAR file) is stored inside GF_HOME\\glassfish\\lib and my EAR file is stored into GF_HOME\\glassfish\\domains\\domain1 . Both JAR and EAR contain log4j.xml file.

My log4j library is in GF_HOME\\glassfish\\domains\\domain1\\lib directory.

I want to handle configuration with 2 log4j.xml file.

So in the log4j.xml file of my SAM I have this :

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

<appender name="FILE" class="org.apache.log4j.RollingFileAppender">
    <param name="File" value="${catalina.home}/logs/sim.log" />
    <param name="Threshold" value="DEBUG" />
    <param name="Append" value="true" />
    <param name="MaxFileSize" value="1MB" />
    <param name="MaxBackupIndex" value="1" />

    <layout class="org.apache.log4j.PatternLayout">
        <param name="ConversionPattern" value="%d %-5p %X{service} %X{user} [%c] %m%n" />
    </layout>
</appender>

<root>
    <priority value="DEBUG" />
    <appender-ref ref="FILE" />
</root>

And in log4j.xml in my app :

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

 <appender name="FILE" class="org.apache.log4j.RollingFileAppender">
    <param name="File" value="${catalina.home}/logs/sim.log"/>
    <param name="Threshold" value="DEBUG"/>
    <param name="Append" value="true"/>
    <param name="MaxFileSize" value="1MB"/>
    <param name="MaxBackupIndex" value="1"/>

    <layout class="org.apache.log4j.PatternLayout">
        <param name="ConversionPattern" value="%d %-5p %X{service} %X{user} [%c] %m%n"/>
    </layout>             
</appender>

<logger name="com.sim" additivity="true">
    <level value="FATAL" />     
</logger>

<root>
    <priority value="DEBUG" />
    <appender-ref ref="FILE" />
</root>

With this configuration I don't expect to see for example levels of INFO or DEBUG in my app because for logger com.sim level is FATAL but I receive all logs because it seems to apply configuration of SAM log4j.xml. Indeed, when I delete this file, I receive logs for my app for level FATAL .

It seems that glassfish "mix" or "merge" all log4j.xml files found. I don't understand well the principle.

I just want to manage my SAM with 1 log4j.xml and manage my app with another independant log4j.xml.

How can I do this?

Answer 1

To answer my post :

Remember that I have EAR file with log4j.xml file inside JAR in lib directory of my EAR.

To apply new log4j configuration, I created new servlet launched at startup and used DOMConfigurator.configure() (notice that if you work with properties file you must use PropertyConfigurator.configure() not DOMConfigurator.configure() ).

Here is my servlet :

public class Log4jInit implements Servlet {

@Override
public void destroy() {}

@Override
public ServletConfig getServletConfig() {return null;}

@Override
public String getServletInfo() {return null;}

@Override
public void init(ServletConfig arg0) throws ServletException {

    try{        
        DOMConfigurator.configure(getClass().getClassLoader().getResource("log4j.xml"));            
    }catch(Exception e){
        System.out.println("Log4jInit Exception : " + e);
    }

}

@Override
public void service(ServletRequest arg0, ServletResponse arg1)  throws ServletException, IOException {}

}

Also, don't forget to modify your web.xml file :

<servlet>
    <servlet-name>Log4j Servlet</servlet-name>
    <servlet-class>your.package.Log4jInit</servlet-class>
    <load-on-startup> 1 </load-on-startup>
</servlet>

And that's all.

If you want to add/override previous log4j configuration, keep this code.

If you want to reset previous configuration, add LogManager.resetConfiguration(); before LogManager.resetConfiguration(...);