在Web应用程序中使用log4j的最佳方法是什么？

Question

We are starting a Spring MVC based web application. We will be using tomcat as the web server.

I need to configure log4j in the application and log to the application specific file and not to the tomcat log files.

eg tomcat has its own log files like localhost.log etc. I want something like myAppName.log in the tomcats log folder.

The logging configuration will go in lo4j.xml or log4j.properties in the application war file.

Plus I dont want to hard code the output log file in the web application.

But I am not sure how to do this.

Please help me. As well correct me if I am wrong somewhere.

Answer 1

Do like this, initialize the logger with following code,

Logger log = Logger.getLogger(this.getClass());

log the information like follows,

log.debug("My message");

and place the log4j.xml in your class path. content like follows,

<log4j:configuration xmlns:log4j="http://jakarta.apache.org/log4j/">
     <appender name="infoLogsFile" class="org.apache.log4j.RollingFileAppender">
         <param name="File" value="MyApplication.log"/>     
         <param name="Threshold" value="DEBUG"/>
         <param name="MaxFileSize" value="100MB"/>
         <param name="ImmediateFlush" value="TRUE"/>
         <layout class="org.apache.log4j.PatternLayout">
           <param name="ConversionPattern" value="%d %-5p [%c] %m%n"/>
         </layout>
    </appender>
   <root> 
      <priority value ="DEBUG" /> 
      <appender-ref ref="infoLogsFile"/>
   </root>
</log4j:configuration>

Do not forget to add the required jars like log4jXXX.jars and apache common logging jars. with this you will be able to see all log messages in MyApplication.log file creates in bin folder of your tomcat.

Answer 2

Try this:

• Put the log4j jar as part of the web application

• Do not put a configuration as part of your web application

• Create your log4j.xml wherever you like

• When you start tomcat provide this argument -Dlog4j.configuration=file:///.../log4j.xml