Filename with date in Log4j

Question

I\'m trying to append the current date to the log4j log file. So it would be something like this:

myApp-2011-01-07.log

The thing is that I do not want to us

Answer 1

Try setting this in your log4j.properties file:

log4j.appender.R=org.apache.log4j.DailyRollingFileAppender
log4j.appender.R.File=example.log

much more information can be found here http://logging.apache.org/log4j/1.2/apidocs/org/apache/log4j/DailyRollingFileAppender.html

Answer 2

I think you could just set a system property in code to contain the current date:

static{
    SimpleDateFormat dateFormat = new SimpleDateFormat("yyyy-MM-dd");
    System.setProperty("current.date", dateFormat.format(new Date()));
}

Then in your log4j.xml file you can use the system property when specifying the log file name in the appender:

<appender name="MYAPPENDER" class="org.apache.log4j.FileAppender">
    <param name="File" value="${user.home}/myApp-${current.date}.log" />

ETA: Now that I think about it you may have to setup the system property using a static initializer to make sure the property is set before log4j is configured.

Answer 3

you can manage this quickly and highly mantainable by just creating your own Appender.

Just create a Class like this :

    import java.text.SimpleDateFormat;
    import java.util.Date;
    import org.apache.log4j.FileAppender;

    public class CustomFileAppender extends  FileAppender{

    @Override
    public void setFile(String fileName)
    {
        if (fileName.indexOf("%timestamp") >= 0) {
            Date d = new Date();
            SimpleDateFormat format = new SimpleDateFormat("yyyyMMddHHmmssSS");
            fileName = fileName.replaceAll("%timestamp", format.format(d));
        }
        super.setFile(fileName);
   }
}

and place this in your properties:

   log4j.appender.file=com.portima.filenet.brio.ops.tools.CustomFileAppender
   log4j.appender.file.File=${log}/general.%timestamp.log

Now you can give any type of filename you want.