<?xml version="1.0"?>
<!DOCTYPE document [
  <!ENTITY project SYSTEM "project.xml">
]>
<document url="logger.html">

  &project;

  <properties>
    <author email="craigmcc@apache.org">Craig R. McClanahan</author>
    <title>The Logger Component</title>
  </properties>

<body>


<section name="Introduction">

  <p>Tomcat uses the 
     <a href="http://jakarta.apache.org/commons/logging/">Commons Logging</a>
     package to implement all logging.  This includes the logging defined
     by <code>ServletContext.log</code>.</p>

  <p>If you are interested in producing access logs like a web server does
  (for example, to run hit count analysis software), you will want to configure
  an <a href="valve.html#Access Log Valve">Access Log Valve</a> component on
  your <a href="engine.html#Access Logs">Engine</a>,
  <a href="host.html#Access Logs">Host</a>, or
  <a href="context.html#Access Logs">Context</a>.</p>

    <blockquote><em>
    <p>The description below uses the variable name $CATALINA_HOME
    to refer to the directory into which you have installed Tomcat 5,
    and is the base directory against which most relative paths are
    resolved.  However, if you have configured Tomcat 5 for multiple
    instances by setting a CATALINA_BASE directory, you should use
    $CATALINA_BASE instead of $CATALINA_HOME for each of these
    references.</p>
    </em></blockquote>

</section>


<section name="Using Log4j">
  <p>One of the options for logging is to use the
     <a href="http://logging.apache.org/log4j/">Log4j</a> package to implement
     the logging for Tomcat.  The simplest way to do this is to copy the
     <code>log4j-x.x.x.jar</code> and the <code>commons-logging.jar</code>
     to <em>$CATALINA_HOME/common/lib</em>.  The <em>log4j.xml</em> file
     can then be placed in <em>$CATALINA_HOME/common/classes</em>.  An example
     configuration is:</p>
     <source>
&lt;?xml version="1.0" encoding="UTF-8" ?&gt;
&lt;!DOCTYPE log4j:configuration SYSTEM "log4j.dtd"&gt;

&lt;log4j:configuration  xmlns:log4j='http://jakarta.apache.org/log4j/'&gt;

	&lt;appender name="STDOUT" class="org.apache.log4j.ConsoleAppender"&gt;
           &lt;layout class="org.apache.log4j.PatternLayout"&gt;
             &lt;param name="ConversionPattern"
		    value="%d %-5p [%t] %c (%F:%L) - %m%n"/&gt;
           &lt;/layout&gt;	    
	&lt;/appender&gt;
        &lt;appender name="catalina" 
                     class="org.apache.log4j.DailyRollingFileAppender"&gt;
          &lt;param name="File" 
                    value="${catalina.home}/logs/catalina_log.txt" /&gt;
          &lt;param name="DatePattern" value="'.'yyy-MM-dd" /&gt;
           &lt;layout class="org.apache.log4j.PatternLayout"&gt;
             &lt;param name="ConversionPattern"
		    value="%-5p %d - %m%n"/&gt;
           &lt;/layout&gt;	    
        &lt;/appender&gt;
        &lt;appender name="localhost" 
                     class="org.apache.log4j.DailyRollingFileAppender"&gt;
          &lt;param name="File" 
                    value="${catalina.home}/logs/localhost_log.txt" /&gt;
          &lt;param name="DatePattern" value="'.'yyy-MM-dd" /&gt;
           &lt;layout class="org.apache.log4j.PatternLayout"&gt;
             &lt;param name="ConversionPattern"
		    value="%-5p %d - %m%n"/&gt;
           &lt;/layout&gt;	    
        &lt;/appender&gt;
        &lt;appender name="localhost.admin" 
                     class="org.apache.log4j.DailyRollingFileAppender"&gt;
          &lt;param name="File" 
                    value="${catalina.home}/logs/localhost_admin_log.txt" /&gt;
          &lt;param name="DatePattern" value="'.'yyy-MM-dd" /&gt;
           &lt;layout class="org.apache.log4j.PatternLayout"&gt;
             &lt;param name="ConversionPattern"
		    value="%-5p %d - %m%n"/&gt;
           &lt;/layout&gt;	    
        &lt;/appender&gt;
	
	&lt;category 
             name="org.apache.catalina.core.ContainerBase.[Catalina]" 
             additivity="false"&gt;
	  &lt;priority value="info" /&gt;
          &lt;appender-ref ref="catalina" /&gt;
	&lt;/category&gt;
	&lt;category 
            name="org.apache.catalina.core.ContainerBase.[Catalina].[localhost]" 
            additivity="false"&gt;
	  &lt;priority value="info" /&gt;
          &lt;appender-ref ref="localhost" /&gt;
	&lt;/category&gt;
	&lt;category 
           name="org.apache.catalina.core.ContainerBase.[Catalina].[localhost].[/admin]" 
           additivity="false"&gt;
	  &lt;priority value="info" /&gt;
          &lt;appender-ref ref="localhost.admin" /&gt;
	&lt;/category&gt;
	
	&lt;root&gt;
	   &lt;priority value ="info" /&gt;
   	   &lt;appender-ref ref="STDOUT" /&gt;
	&lt;/root&gt;
	
&lt;/log4j:configuration&gt;
     </source>
</section>


<section name="Using JDK1.4 logging">

  <p><strong>TO DO</strong></p>

</section>


</body>


</document>