Sample xml configuration for log4j, have a 'main' java application and want to write to file

Question

Are there any example log4j configuration files (XML).

I have a java main application.

I want log4j to output to console AND write to file.

Any examples of this would be greatly appreciated.

I'm using netbeans if that matters.

Answer 1

Just have more than one appender in your log4j.xml, like this:

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE log4j:configuration SYSTEM "log4j.dtd">
<log4j:configuration debug="true"
                     xmlns:log4j='http://jakarta.apache.org/log4j/'>

   <appender name="consoleAppender" class="org.apache.log4j.ConsoleAppender">
      <layout class="org.apache.log4j.PatternLayout">
         <param name="ConversionPattern" value="%d{dd MMM yyyy HH:mm:ss} %5p %c{1} - %m%n"/>
      </layout>
   </appender>

   <appender name="fileAppender" class="org.apache.log4j.RollingFileAppender">
      <param name="append" value="false"/>
      <param name="file" value="out/learning.log"/>
      <layout class="org.apache.log4j.PatternLayout">
         <param name="ConversionPattern" value="%d{ABSOLUTE} %-5p [%c{1}] %m%n"/>
      </layout>
   </appender>

   <root>
      <level value="INFO"/>
      <appender-ref ref="consoleAppender"/>
      <appender-ref ref="fileAppender"/>
   </root>

</log4j:configuration>

Answer 2

Here is one sample example of log4j.xml used in Hibernate project.Just need to place this file in classpath and you will get log messages on console as well as in file also.If you want any specific appender you can change in tag.

<?xml version="1.0" encoding="UTF-8"?>  
<!DOCTYPE log4j:configuration SYSTEM "log4j.dtd">  
<log4j:configuration xmlns:log4j="http://jakarta.apache.org/log4j/"  
    debug="false">  
<appender name="CONSOLE" class="org.apache.log4j.ConsoleAppender">  
 <layout class="org.apache.log4j.PatternLayout">  
  <param name="ConversionPattern" value="[%d{dd/MM/yy hh:mm:ss:sss z}] %5p %c{2}: %m%n" />  
 </layout>  
</appender>  
    <appender name="ASYNC" class="org.apache.log4j.AsyncAppender">  
        <appender-ref ref="CONSOLE" />  
        <appender-ref ref="FILE" />  
</appender>  
<appender name="FILE" class="org.apache.log4j.RollingFileAppender">  
    <param name="File" value="C:/hibernatelog.log"/>  
    <param name="MaxBackupIndex" value="100" />  
 <layout class="org.apache.log4j.PatternLayout">  
  <param name="ConversionPattern" value="[%d{dd/MM/yy hh:mm:ss:sss z}] %5p %c{2}: %m%n" />  
</layout>  
</appender>  
    <category name="org.hibernate">  
        <priority value="DEBUG" />  
    </category>  
    <category name="java.sql">  
        <priority value="debug" />  
    </category>  
    <root>  
        <priority value="INFO" />  
        <appender-ref ref="ASYNC" />  
    </root>  
</log4j:configuration>  

I found this one more descriptive then above one.Hope it help.