Setting a log file name to include current date in Log4j

Question

I would like to set the log file name for a log4j and log4net appender to have the current date. We are doing Daily rollovers but the current log file does not have a date. The log file name format would be

logname.2008-10-10.log

Anyone know the best way for me to do this?

edit: I forgot to mention that we would want to do this in log4net as well. Plus any solution would need to be usable in JBoss.

Secede

Answer 1

DailyRollingFileAppender is what you exactly searching for.

<appender name="roll" class="org.apache.log4j.DailyRollingFileAppender">
    <param name="File" value="application.log" />
    <param name="DatePattern" value=".yyyy-MM-dd" />
    <layout class="org.apache.log4j.PatternLayout"> 
      <param name="ConversionPattern" 
          value="%d{yyyy-MMM-dd HH:mm:ss,SSS} [%t] %c %x%n  %-5p %m%n"/>
    </layout>
  </appender>

Blabbermouth

Won't this simply create a log file called "application.log" and only place the datepattern in the rolled log files? – Secede

As a result you will get a separate log file for each day. But the todays log file will be named as application.log, without a date. And it's ok in most cases. – Blabbermouth

Two comments on "DatePattern": - I use ".yyyy-MM-dd.lo\g" to get the same extension for all log files. - The backslash before g is needed (at least for log4net) to prevent .Net applying the predefined "g" format. – Krakau

@gyrolf, applying the format you mention, do your logs end up as mylog.log.yyyy-MM-dd.log? Or are you somehow removing the previous extension? – Stickup

From log4j docs: DailyRollingFileAppender has been observed to exhibit synchronization issues and data loss.(logging.apache.org/log4j/1.2/apidocs/org/apache/log4j/…). you should really follow @Phonology answer – Pion

This is not what the OP asks for. This solution will not have the current date. – Labrum

@JamesMcMahon I've used log4j with a log4j.properties file like so: log4j.appender.roll.datePattern='.'yyyy-MM-dd'.txt' and yes this results in a file name like application.log.2016-01-25.log – Foam

Answer 2

Using log4j.properties file, and including apache-log4j-extras 1.1 in my POM with log4j 1.2.16

log4j.appender.LOGFILE=org.apache.log4j.rolling.RollingFileAppender
log4j.appender.LOGFILE.RollingPolicy=org.apache.log4j.rolling.TimeBasedRollingPolicy
log4j.appender.LOGFILE.RollingPolicy.FileNamePattern=/logs/application_%d{yyyy-MM-dd}.log

Phonology

^---^ Pro level: 99 log4j.appender.out.RollingPolicy.FileNamePattern=logs/%d{yyyy-MM-dd HH-mm-ss} cron-script-x/out.log log4j.appender.err.RollingPolicy.FileNamePattern=logs/%d{yyyy-MM-dd HH-mm-ss} cron-script-x/err.log – Gestalt

As of right now, the download mirrors links are all broken. You can still find the library in the archive repository: archive.apache.org/dist/logging/log4j/companions/extras – Height

log4j.appender..DatePattern=yyyy-MM-dd will do the trick. File name will roll every day and no need for additional dependency – Isabeau

Answer 3

I'm 99% sure that RollingFileAppender/DailyRollingFileAppender, while it gives you the date-rolling functionality you want, doesn't have any way to specify that the current log file should use the DatePattern as well.

You might just be able to simply subclass RollingFileAppender (or DailyRollingFileAppender, I forget which is which in log4net) and modify the naming logic.

Sanitize

Answer 4

I have created an appender that will do that. http://stauffer.james.googlepages.com/DateFormatFileAppender.java

/*
 * Copyright (C) The Apache Software Foundation. All rights reserved.
 *
 * This software is published under the terms of the Apache Software
 * License version 1.1, a copy of which has been included with this
 * distribution in the LICENSE.txt file.  */

package sps.log.log4j;

import java.io.IOException;
import java.io.File;
import java.text.SimpleDateFormat;
import java.util.Date;

import org.apache.log4j.*;
import org.apache.log4j.helpers.LogLog;
import org.apache.log4j.spi.LoggingEvent;

/**
 * DateFormatFileAppender is a log4j Appender and extends 
 * {@link FileAppender} so each log is 
 * named based on a date format defined in the File property.
 *
 * Sample File: 'logs/'yyyy/MM-MMM/dd-EEE/HH-mm-ss-S'.log'
 * Makes a file like: logs/2004/04-Apr/13-Tue/09-45-15-937.log
 * @author James Stauffer
 */
public class DateFormatFileAppender extends FileAppender {

  /**
   * The default constructor does nothing.
   */
  public DateFormatFileAppender() {
  }

  /**
   * Instantiate a <code>DailyRollingFileAppender</code> and open the
   * file designated by <code>filename</code>. The opened filename will
   * become the ouput destination for this appender.
   */
  public DateFormatFileAppender (Layout layout, String filename) throws IOException {
    super(layout, filename, true);
  }

  private String fileBackup;//Saves the file pattern
  private boolean separate = false;

  public void setFile(String file) {
    super.setFile(file);
    this.fileBackup = getFile();
  }

  /**
   * If true each LoggingEvent causes that file to close and open.
   * This is useful when the file is a pattern that would often
   * produce a different filename.
   */
  public void setSeparate(boolean separate) {
    this.separate = separate;
  }

  protected void subAppend(LoggingEvent event) {
    if(separate) {
        try {//First reset the file so each new log gets a new file.
            setFile(getFile(), getAppend(), getBufferedIO(), getBufferSize());
        } catch(IOException e) {
            LogLog.error("Unable to reset fileName.");
        }
    }
    super.subAppend(event);
  }


  public
  synchronized
  void setFile(String fileName, boolean append, boolean bufferedIO, int bufferSize)
                                                            throws IOException {
    SimpleDateFormat sdf = new SimpleDateFormat(fileBackup);
    String actualFileName = sdf.format(new Date());
    makeDirs(actualFileName);
    super.setFile(actualFileName, append, bufferedIO, bufferSize);
  }

  /**
   * Ensures that all of the directories for the given path exist.
   * Anything after the last / or \ is assumed to be a filename.
   */
  private void makeDirs (String path) {
    int indexSlash = path.lastIndexOf("/");
    int indexBackSlash = path.lastIndexOf("\\");
    int index = Math.max(indexSlash, indexBackSlash);
    if(index > 0) {
        String dirs = path.substring(0, index);
//        LogLog.debug("Making " + dirs);
        File dir = new File(dirs);
        if(!dir.exists()) {
            boolean success = dir.mkdirs();
            if(!success) {
                LogLog.error("Unable to create directories for " + dirs);
            }
        }
    }
  }

}

Hawkshaw

Answer 5

I don't know if it is possible in Java, but in .NET the property StaticLogFileName on RollingFileAppender gives you what you want. The default is true.

<staticLogFileName value="false"/>

Full config:

<appender name="DefaultFileAppender" type="log4net.Appender.RollingFileAppender">
  <file value="application"/>
  <staticLogFileName value="false"/>
  <appendToFile value="true" />
  <rollingStyle value="Date" />
  <datePattern value="yyyy-MM-dd&quot;.log&quot;" />
  <layout type="log4net.Layout.PatternLayout">
    <conversionPattern value="%date [%thread] %-5level %logger [%property{NDC}] - %message%newline" />
  </layout>
</appender>

".log" is for not letting the dateformat recognice the global date pattern 'g' in log.

Electrodynamic

Just for clarification: Are the HTML entities &quot in yyyy-MM-dd".log" meant to be there, instead of '? – Bren

Answer 6

this example will be creating logger for each minute, if you want to change for each day change the DatePattern value.

<appender name="ASYNC" class="org.apache.log4j.DailyRollingFileAppender">
   <param name="File" value="./applogs/logger.log" />
   <param name="Append" value="true" />
   <param name="Threshold" value="debug" />
   <appendToFile value="true" />
   <param name="DatePattern" value="'.'yyyy_MM_dd_HH_mm"/>
   <rollingPolicy class="org.apache.log4j.rolling.TimeBasedRollingPolicy">
      <param name="fileNamePattern" value="./applogs/logger_%d{ddMMMyyyy HH:mm:ss}.log"/>
      <param name="rollOver" value="TRUE"/>
   </rollingPolicy>
   <layout class="org.apache.log4j.PatternLayout">
      <param name="ConversionPattern" value="%d{ddMMMyyyy HH:mm:ss,SSS}^[%X{l4j_mdc_key}]^[%c{1}]^ %-5p %m%n" />
   </layout>
</appender>
<root>
   <level value="info" />
   <appender-ref ref="ASYNC" />
</root>

Weisshorn

Answer 7

As a response to the two answers which mention DailyRollingFileAppender (sorry, I don't have enough rep to comment on them directly, and I think this needs to be mentioned), I would warn that unfortunately the developers of that class have documented that it exhibits synchronization and data loss, and recommend that alternatives should be pursued for new deployments.

DailyRollingFileAppender JavaDoc

Amesace

Answer 8

You can set FileAppender dynamically

SimpleLayout layout = new SimpleLayout();           
FileAppender appender = new FileAppender(layout,"logname."+new Date().toLocaleString(),false);
logger.addAppender(appender); 

Tiffie

Be carefull with the slashes "/" in the file name. I would rather user: "logname"+new Date().format("yyyy-mm-dd-hh-MM")+".log" – Oldster

This will create new log file only on app start and will not cut your logs to files by date – Streeto

Answer 9

just use TimeBasedRollingPolicy and don't use param name="File"

  <appender name="pdi-execution-appender" class="org.apache.log4j.rolling.RollingFileAppender">   
        <!-- The active file to log to; this example is for Pentaho Server.-->
        <param name="Append" value="true" />
        <param name="Threshold" value="INFO"/>
        <rollingPolicy class="org.apache.log4j.rolling.TimeBasedRollingPolicy">
            <!-- See javadoc for TimeBasedRollingPolicy -->
            <param name="FileNamePattern" value="logs/ETL-LogFile.%d{yyyyMMdd}.log" />
        </rollingPolicy>
        <layout class="org.apache.log4j.PatternLayout">
            <param name="ConversionPattern" value='%d{yyyy-MM-dd HH:mm:ss.SSS} %-5p [%t] %m'/>
        </layout>
  </appender>

Selfpreservation

Answer 10

Even if you use DailyRollingFileAppender like @gedevan suggested, you will still get logname.log.2008-10-10 (After a day, because the previous day log will get archived and the date will be concatenated to it's filename).

So if you want .log at the end, you'll have to do it like this on the DatePattern:

log4j.appender.file.DatePattern='.'yyyy-MM-dd-HH-mm'.log'

Empirical

Answer 11

You can do it programmatically like so:

        String dateFile = LocalDate.now().toString() + ".log";
        Enumeration enm = Logger.getRootLogger().getAllAppenders();
        Appender appender = null;
        while(enm.hasMoreElements()){
            appender = (Appender)enm.nextElement();
            String c = appender.getClass().toString();
            if(c.contains("FileAppender")){
                String f = ((FileAppender)appender).getFile();
                ((FileAppender)appender).setFile(f+dateFile);
                System.out.println("From:"+f+" to:"+dateFile);
            }
        }

Borries